# High Amperage on 200 volt 3ph Fire Pump Motor



## Southeast Power (Jan 18, 2009)

200 volt
three phase
167 amps rated at full load
incoming voltage 205

no load 127 amps
Under load 460 amps!

I was called out to check out an overheating fire pump motor that had recently been serviced by a local motor shop.
The motor has six leads and is correctly wired for "across the line start" per the name plate.
I megged each sets of leads at the fire pump controller to ground at 1000 volts, it climbed to 199.9 and then went "OL".

The problem:

The motor runs smooth and draws roughly 127 amps per leg with no load on the pump head.
The fire sprinkler guy opened the 2 1/2" test valve located on the roof of the 12 story building and the current spiked to 460 amps. The voltage dropped to 192 amps and the fire pump controller began to go into alarm.
As soon as the sprinkler guy closed the valve, the amperage returned to 127 or so amps.

The motor shaft can be turned and does not seem to be dragging.

The pump controller has a resister bank built into it. It comes on line in parallel with the motor when it starts, then drops out after a few seconds when the motor runs. It appears to be operating properly.

I do not know what services the motor shop provided. The owner said that they "rebuilt" it.

Any insight would be appreciated.


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## Big John (May 23, 2010)

jrannis said:


> ...The voltage dropped to 192... The pump controller has a resister bank built into it. It comes on line in parallel with the motor when it starts, then drops out after a few seconds when the motor runs. It appears to be operating properly.


 I take it you measured 192 volts at the line side of the pump controller? 

And what makes you say the resistor bank is working? Because first guess is it sounds like the motor is going directly across the line.

-John


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## Southeast Power (Jan 18, 2009)

Big John said:


> I take it you measured 192 volts at the line side of the pump controller?
> 
> And what makes you say the resistor bank is working? Because first guess is it sounds like the motor is going directly across the line.
> 
> -John


Thanks John,

The pump controller has a handle that will allow the pump to be started without the automatic feature and not engaging the resister bank for starting.
I tried this feature and had the same readings.

Is your concern that the resister bank is not in the circuit or that it is not dropping out?
Im not sure of the theory behind the resister bank.


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## Big John (May 23, 2010)

The resistor bank goes in series with the pump motor and acts like a soft-start. It reduces the voltage across the pump allowing it to spin up more slowly at a lower current.

Without it, you'd get a heck of a lot of current at startup.

That you can intentionally start the pump without the resistor bank and still get these readings really suggests the bank is never connecting.  Find the contactor that controls the resistors and check to see if it's actually pulling in.

-John


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## McClary’s Electrical (Feb 21, 2009)

Is this a VFD? If so, I bet your readings are not accurate.


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## Southeast Power (Jan 18, 2009)

Its a simple contactor that operates the pump and another one that is in parallel with it for the resister bank.

We started the pump and let it run for several minutes without a load and then had the sprinkler guy go up to the roof and open the valve.

Would the absence of the resister bank affect the motor 10 or so minutes after starting?

I could be mis-stating the "parallel" connection of the resister bank due to it being connected to the same load terminals as the motor conductors. I now see how it could be in series. I should have taken a pic.


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## Southeast Power (Jan 18, 2009)

Big John said:


> I take it you measured 192 volts at the line side of the pump controller?
> 
> And what makes you say the resistor bank is working? Because first guess is it sounds like the motor is going directly across the line.
> 
> -John


I read the controller and the CTs for the current readings are on the load side of the breaker before the resister and the motor.


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## CFL (Jan 28, 2009)

The resistors are usually on a timer aren't they? They would never be on for ten minutes, and they wouldn't come on when they see a load. They come on during startup and time out.


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## CFL (Jan 28, 2009)

How long did it run while drawing 460amps? Is it possible it would have dropped back down once it reached full speed?


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## Big John (May 23, 2010)

Nuts, I forgot you said this happens after the pump is already running.

Did you notice if both contactors were pulled in at the same time?

-John


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## Southeast Power (Jan 18, 2009)

The motor comes up to speed very fast. I see where a problem could occur if the resisters stayed in the circuit. I just cant understand why the current would rise that much when a load was put on it.
It will stay at 460 amps until the valve is closed.


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## Wirenuting (Sep 12, 2010)

Is there an unloading loop for the water?
Is it staying open when the test valve is opened?
Can you open a test valve at ground level?
Is the 12 story test valve to large? How many heads is this pump rated for? 

And lastly, is the transformer large enough to carry the load?
I ask that one because in 99 the 200V pump in a 12 story hospital had a similar issue. 
We stress tested the transformer and the problem only worsened over time. 
But we had 4 power centers with 2 risers and interconnected them together. Share the load and hid the problem until the moved it outside. Installed a diesel pump.


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## JRaef (Mar 23, 2009)

Who determined that opening a test valve wide open is a valid system test? Did anyone check this procedure out with the pump supplier?

In a pump system, LOAD on the motor varies by the cube of the FLOW, which is affected by HEAD. So your pump has to create enough pressure to overcome the head pressure, but once you do that, then the amount of flow determines the load. If the pump was sized to provide maximum flow for all of the SPRINKLERS connected to the system, which only allow a certain amount of flow though them at the pressure developed by the pump, then opening a test valve wide open and dumping all the water unrestricted may end up overloading the motor! 

So you are at roughly 275% rated current on that motor (460/167) and if we equate that to load (although it's no going to be linear), that means you only have to have an increased flow of 140% with the valve open compared to what the sprinklers would allow (1.40 cubed). That's not much and it's easy for that to be the case in a fire system design. Over size the pump by a 20% fudge factor, then oversize the pipe by a 20% fudge factor, bingo. The pump will try to push 40% more water out of that unrestricted pipe than it is capable of with that motor, which pushes the motor to 275% of it's capacity. 

Usually you do a system test at RATED FLOW using a flow meter.


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## Southeast Power (Jan 18, 2009)

The only think different in this property is that the fire pump went out to be "re-built" and a new fire pump controller was installed.
The test pipe is 2 1/2" and we believe this would put about 40% load on the pump motor.
We did not think to mention the unloading loop

FP&L was on site and they only had one or two volts dropped at the transformer vault load side when the pump was drawing the high amperage.


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## Motorwinder (Dec 30, 2010)

60 hp? Sounds like a connection problem in the motor. 

Whats the markings on the leads? The no-load amps seems high.

Full name plate data would help. Was it burnt when they pulled it? Did you check the contacts in the starter? Try to find out if they rewound it.


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## Big John (May 23, 2010)

_Jraef_, I don't know if that's the problem, but that was an interesting post. I had no idea an unrestricted pump could actually cause an overload. Does that only apply to centrifugal pumps?

-John


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## RIVETER (Sep 26, 2009)

jrannis said:


> 200 volt
> three phase
> 167 amps rated at full load
> incoming voltage 205
> ...


When the motor is running, how are you separating it from the load?


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## CFL (Jan 28, 2009)

RIVETER said:


> When the motor is running, how are you separating it from the load?


By keeping the test valve closed.


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## RIVETER (Sep 26, 2009)

CFL said:


> By keeping the test valve closed.


I have not done those types of tests but are you saying that you run the pump against a "dead" head and check the current?


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## Wirenuting (Sep 12, 2010)

RIVETER said:


> I have not done those types of tests but are you saying that you run the pump against a "dead" head and check the current?


The larger ones I have seen have a relief loop for the water to flow thru. 
The water will heat up over time but the fire dept should be on scene.
The pumps can dead head and not overload. The idea is one sprinkler head will start the pump and she will run forever.
A lack of back pressure can easily cause it to over current. 
The only fire pumps I have seen or heard of that are designed for a volume of full flow/pressure thru the system and not over load are deluge systems and magazine sprinklers.
Fire pumps are designed to help protect the structure long enough for the fire dept to arrive. They are designed to "run to destruction". 
They are not designed to save lives.

That's how ours was in the 12 story hospital I worked at. I believe it was a 200hp @ 200v. 
We had no emergency power for it. It was installed beyond what I had available with my 3 generators. 
No body asked me before they installed it.


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## RIVETER (Sep 26, 2009)

Wirenuting said:


> The larger ones I have seen have a relief loop for the water to flow thru.
> The water will heat up over time but the fire dept should be on scene.
> The pumps can dead head and not overload. The idea is one sprinkler head will start the pump and she will run forever.
> A lack of back pressure can easily cause it to over current.
> ...


I am not a fire pump person, or a plumber or the like but why would you put a pump in place for anything other than it's potential? It seems to me that it's full load current would be with all valves open and water flowing.


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## Wirenuting (Sep 12, 2010)

RIVETER said:


> I am not a fire pump person, or a plumber or the like but why would you put a pump in place for anything other than it's potential? It seems to me that it's full load current would be with all valves open and water flowing.


It's almost unheard of to pop all the sprinkler heads at one time. They are temp activated. 
Remember the idea is to suppress the fire for only a short time and save the structure.


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## RIVETER (Sep 26, 2009)

Wirenuting said:


> It's almost unheard of to pop all the sprinkler heads at one time. They are temp activated.
> Remember the idea is to suppress the fire for only a short time and save the structure.


So, you are saying that the pump must have the capacity to supply...possibly... 100 heads, but if only one zone...maybe 20 heads, is activated, the motor won't be overloaded...current wise?


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## Wirenuting (Sep 12, 2010)

RIVETER said:


> So, you are saying that the pump must have the capacity to supply...possibly... 100 heads, but if only one zone...maybe 20 heads, is activated, the motor won't be overloaded...current wise?


That's pretty much how it was explained to me. 
The engineer decides how many may pop at once. It's based on location and space utilization. Size of a space is of second consideration as the heads can be directional or shaped to confine the fire.
ie: water curtain in a hotel hallway.


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## RIVETER (Sep 26, 2009)

Wirenuting said:


> That's pretty much how it was explained to me.
> The engineer decides how many may pop at once. It's based on location and space utilization. Size of a space is of second consideration as the heads can be directional or shaped to confine the fire.
> ie: water curtain in a hotel hallway.


OK, I get it. Thanks.


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## JRaef (Mar 23, 2009)

Big John said:


> Jraef, I don't know if that's the problem, but that was an interesting post. I had no idea an unrestricted pump could actually cause an overload. Does that only apply to centrifugal pumps?
> 
> -John


Yes. Centrifugal only. It called the Affinity Law (or rather one of them). Power varies by the cube of the flow. And since flow and motor speed follow pretty closely, that's why VFDs save a lot of energy in centrifugal pumps and fans. At 1/2 speed the hp requirement drops to 1/8th (.5 x .5 x .5). But it's also something that people don't realize when they use a VFD to run a pump at more than base speed.


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## Southeast Power (Jan 18, 2009)

I have a meeting setup for tomorrow morning. I will investigate the series resister and measure the amperage values on the conductors feeding the pump and compare them to the conductors feeding the pump controller. If the theory established here proves to be true, I suspect that we will find the resister remains in the circuit while the pump is operating.

BTW, the same sprinkler guy has been testing this same pump for years by opening the test valve and has not had a high amperage/ low voltage incident. 
Also, one of the other symptoms I mentioned is that the pump motor gets extremely hot.
I also understand, that the load, as far as how many sprinkler heads vs water column needs to be properly calculated. I was thinking that maybe the test pipe size was calculated for the load.


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## JRaef (Mar 23, 2009)

The resistors indicate you have a Primary Resistor type Reduced Voltage Starter, they used to be common on Fire Pump controllers. If the resistors were stuck in the circuit and the main Run contactor was closed, it would make no difference. The main contactor would be the path of least resistance and the resistors would be meaningless. But if it were stuck on and the main Run contactor didn't pull in, then you would have low voltage at the motor terminals, like 25% voltage (depends on the resistor value) and the pump would never finish accelerating. On addition those resistors ate only rated for a very short duty cycle, they would burn up if left on for even a few minutes I wouldn't put a lot of hope with that being the problem.


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## frenchelectrican (Mar 15, 2007)

I know someone mention 2.5 inch pipe however if you open that test valve on top of 12 th story and use the flow/ pressure meter you should able record it and throttle it a bit to the point where you get max current drawage on the motor nameplate and leave it there it will not get overloaded.

But if you ran the test valve wide open or unthrottled that where the issue will arise.

I am sure one of our member in the fourm will assist you with few hard numbers due he work in Fire Dept if my memory serve me right. ( Rsqcapt19 I think if that is correct if so I will ping him real quick so you can get more details asap)

Merci,
Marc


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## Southeast Power (Jan 18, 2009)

OK, the theory that the resister bank staying engaged may have just been crushed. 
The pump could be designed for just one or two popped sprinkler heads plus what ever water column that exists.
If we are artificially creating an oversize water event by completely opening the test valve, we may unknowingly be overloading the pump. 
It pains me to think that the sprinkler guy must have known something about these types of tests.

I also want to add that I noticed a burning paint smell in the fire pump room but it appeared to be from the freshly painted pump motor and not the resister bank.

I will measure the voltage and current at the motor this morning anyway, it could confirm Marc's post about overloading the pump.

Thanks again for the help guys!


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## JRaef (Mar 23, 2009)

jrannis said:


> ...The pump could be designed for just one or two popped sprinkler heads plus what ever water column that exists.
> If we are artificially creating an oversize water event by completely opening the test valve, we may unknowingly be overloading the pump.
> It pains me to think that the sprinkler guy must have known something about these types of tests....


It might also be that in the past, he didn't open the valve all the way and doesn't remember that. The usual acceptance test I've been involved in with Fire Pumps have been as French Electrician described: open the valve slowly until the pump produces maximum rated flow. The Sprinkler Guys probably never cared enough about that detail to pay attention. But the Fire Pump Guys did because that's what they get paid for, so they would watch a flow meter while the Sprinkler Guy opened the valve. The design specs for the Fire Pump would dictate the maximum flow at the necessary head, so they would simulate that with the flood valve and I would be called upon to check the motor current once they reached the design spec and if we were under FLA, the Engineer would sign off and everyone got paid. 

In this case because you were dealing with a re-wound motor, there probably was no Pump Guy present. So the Sprinkler guy, who likely doesn't understand the flow issue, didn't realize he can't just crank it wide open. He's probably used to a Pump guy telling him what to do.


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## John Valdes (May 17, 2007)

John, Close the valve and start the motor. Have someone slowly open the valve in increments and watch the current. As the valve opens the current rises. Once the current reaches max from nameplate, FLA, this is the amount of flow the pump and motor are designed to push.
Your issue is you are allowing to much flow which results in to much work. Reduce work, you reduce current. 
I would bet if you had a flow meter installed in the discharge line on the roof, it would match max flow to max current. Simple principle of "Work" or "Load" Same thing. 
Jraef is saying the same thing except he is being more technical. 

In the same regard, with the valve completely closed, no current would exist. Water must be moving for work to be accomplished. 
To much flow results in to much work which in turn draws to much current.


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## McClary’s Electrical (Feb 21, 2009)

John Valdes said:


> In the same regard, with the valve completely closed, no current would exist.


I don't agree with that part of your post.


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## John Valdes (May 17, 2007)

mcclary's electrical said:


> I don't agree with that part of your post.


No water flow, no current. Simple as that. The motor current with no load would still exist, if that's what you mean. Then yes, you would have some current.


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## Southeast Power (Jan 18, 2009)

I did the test today. All of the information gleaned here I used. Of course, that was it. The Sprinkler guy didn't have a clue as to what effect the 12 story head had on the flow he expected. He expected the pump to keep up with the 2-1/2" valve he open which was mounted on a six inch pipe.

The building next to the one we tested, had the same company testing the fire pump.
No data was recorded at that building that could help us. We have another test setup on the second building.
I am sure the equipment is rock solid and the testing procedure, which at best is non-existent, could destroy the 60hp pump.

Stay tuned..


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## McClary’s Electrical (Feb 21, 2009)

John Valdes said:


> No water flow, no current. Simple as that. The motor current with no load would still exist, if that's what you mean. Then yes, you would have some current.


 

Yeah, that's what I meant. 

And I knew that you didn't actually mean the motor would use "0.0" current just because water was not flowing.


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## frenchelectrican (Mar 15, 2007)

jrannis said:


> I did the test today. All of the information gleaned here I used. Of course, that was it. The Sprinkler guy didn't have a clue as to what effect the 12 story head had on the flow he expected. He expected the pump to keep up with the 2-1/2" valve he open which was mounted on a six inch pipe.


With the sprinkler guy he may not be well aware with water flowage can really affect the pump performace.

2.5 test port on 6 inch pipe that result a heckva large volume of water which it will be more than 400 GPM { gallons per min } depending on the PSI at the test port and that stated on unthrottled postion on the valve.




> The building next to the one we tested, had the same company testing the fire pump.
> No data was recorded at that building that could help us. We have another test setup on the second building.
> I am sure the equipment is rock solid and the testing procedure, which at best is non-existent, could destroy the 60hp pump.
> 
> Stay tuned..


Eh I hope that you mention to the spinkler guy with the result of 60 HP pump if he ran that unthrottled that can destory the pump by serious overload.

Really I think someone should done recording the doucoment on the testing and I know NFPA have guideline on pump testing producures and the other source you can check is Fire Department they will be more than glad to assit you on this matter as well.

Let us know how it come out with test result.

Merci,
Marc


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## Big John (May 23, 2010)

Jrannis, you learn anything else about this or was this case-closed as too much flow?

-John


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## wdestar (Jul 19, 2008)

I didn't read all the posts that carefully, so pardon the ignorance. If the pump was designed to run at 50 hertz, you'd have big problems running it at 60 Hz.


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## JRaef (Mar 23, 2009)

wdestar said:


> I didn't read all the posts that carefully, so pardon the ignorance. If the pump was designed to run at 50 hertz, you'd have big problems running it at 60 Hz.


I think you replied to the wrong thread.


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## jmsmith (Sep 10, 2011)

Motorwinder said:


> 60 hp? Sounds like a connection problem in the motor.
> 
> Whats the markings on the leads? The no-load amps seems high.
> 
> Full name plate data would help. Was it burnt when they pulled it? Did you check the contacts in the starter? Try to find out if they rewound it.


Another question... Has the pump itself been rebuilt? The impeller in a centrifugal pump is designed to provide lift to a certain head and pressure for a given HP and RPM. If a smaller impeller is installed by mistake, or worn beyond tolerance, it will be an added load on the motor. As it stands now, you are already drawing full load current on this motor. You should NOT be seeing 167A on this motor with NO flow! A quick check would be to uncouple the motor from the pump and try it... I bet you'll see that current drop to around the "idle value". If it stays hi... There is a motor problem. If it comes down, then there is a pump problem. Also, check the plate on the pump and motor to make sure the rated RPMS match. I've seen cases of a 3600RPM motor matched with a pump rated to run at 1800RPM. This is a a case where twice as fast doesn't make it twice as good! :laughing:


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## jmsmith (Sep 10, 2011)

jmsmith said:


> Another question... Has the pump itself been rebuilt? The impeller in a centrifugal pump is designed to provide lift to a certain head and pressure for a given HP and RPM. If a smaller impeller is installed by mistake, or worn beyond tolerance, it will be an added load on the motor. As it stands now, you are already drawing full load current on this motor. You should NOT be seeing 167A on this motor with NO flow! A quick check would be to uncouple the motor from the pump and try it... I bet you'll see that current drop to around the "idle value". If it stays hi... There is a motor problem. If it comes down, then there is a pump problem. Also, check the plate on the pump and motor to make sure the rated RPMS match. I've seen cases of a 3600RPM motor matched with a pump rated to run at 1800RPM. This is a a case where twice as fast doesn't make it twice as good! :laughing:


Sorry, meant 127A. But still, the current should be reading less with all valves closed. Sorry 'bout that!


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## JRaef (Mar 23, 2009)

jmsmith said:


> Sorry, meant 127A. But still, the current should be reading less with all valves closed. Sorry 'bout that!


You seemed to have missed the fact that in post #35 the OP said he determined that the problem was indeed the excess flow from the valve being too wide open.


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## jmsmith (Sep 10, 2011)

Sorry, my bad... But I would like to know what his current wound-up being with all valves closed. If that motor is still drawing 127a at "idle" (no flow), then the op still may have a pump issue. A centrifugal pump does not load a motor @ 76% of its full load current with no flow. I have seen this in several mills, refineries, and different chemical plants. The only style of pump that loads a motor this heavy are positive-displacement (gear pumps, Lapp pumps, etc.). That is why these pumps auto-bypass valving to prevent case or pipe rupture from overpressure. Was just trying to be of a little help here, that's all.


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## Wirenuting (Sep 12, 2010)

Here is a snap of a 60HP fire pump test sheet. It shows the correlation of flow, pressure & amperage. 
It rises as flow increased.


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## jmsmith (Sep 10, 2011)

Wirenuting said:


> Here is a snap of a 60HP fire pump test sheet. It shows the correlation of flow, pressure & amperage.
> It rises as flow increased.


Thank you! I was trying to explain that there still might be a problem with the pump that still has not been addressed. The 0GPM current load on the motor is less than 50% of full load current. Even though this is at 480V, the same should apply for ANY 3-phase motor. I would expect to see closer to 80-85A @0GPM, not the 127A that the op was seeing.


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## Wirenuting (Sep 12, 2010)

I agree, but keep in mind that "my" zero flow rate is thru the churn loop. 

It's zero flow from the system, and yet ??? gpm thru the loop at the pump. This motor is also 480, but I didn't look at the data plate for fla. But you het the idea


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## jmsmith (Sep 10, 2011)

Wirenuting said:


> I agree, but keep in mind that "my" zero flow rate is thru the churn loop.
> 
> It's zero flow from the system, and yet ??? gpm thru the loop at the pump. This motor is also 480, but I didn't look at the data plate for fla. But you het the idea


The churn loop you are referring to is the equivalent to what we used to refer to as bypass loops. In either case, flow will actually be 0GPM once the piping is full and you have reached line pressure. Once you reach this point, the impeller is just spinning in the pump casing and fluid no longer being moved. So you really have a flow of 0GPM. Now, going the other way, we used to use this to protect pumps in the petrochemical industry. When there is NO FLUID on the suction side of the pump, and that will burn-up seals in a heartbeat. This will allow the current to drop even further. This allowed us to install current cutout relays in the motor control circuit to shutdown the pump in the event of this happening. What was the correct setting for these? When the current would drop below 40% of full-load current for a minimum of 5sec.


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## jmsmith (Sep 10, 2011)

BTW, sir, I'd just about be willing to bet if you had pressure gauges on both the suction and discharge sides of the pump, the pressures would read the same on both sides of the pump. This would also be a reliable indicator of 0(units) flow. No differential pressure in a closed system = no flow.


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## Wirenuting (Sep 12, 2010)

jmsmith said:


> The churn loop you are referring to is the equivalent to what we used to refer to as bypass loops. In either case, flow will actually be 0GPM once the piping is full and you have reached line pressure. Once you reach this point, the impeller is just spinning in the pump casing and fluid no longer being moved. So you really have a flow of 0GPM. Now, going the other way, we used to use this to protect pumps in the petrochemical industry. When there is NO FLUID on the suction side of the pump, and that will burn-up seals in a heartbeat. This will allow the current to drop even further. This allowed us to install current cutout relays in the motor control circuit to shutdown the pump in the event of this happening. What was the correct setting for these? When the current would drop below 40% of full-load current for a minimum of 5sec.


Here we don't install the cutout relays. Here we run to destruction. Once a pump kicks on you have to manually secure it. 

And we also call that bypass loop the test loop. Your right about no flow burning out the seals and bearings. She gets hot real quick when the loop is closed by mistake. 

We had one starter here that had the resister bank. I swung by that building today and it's gone. I'll search more tomorrow.


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## jmsmith (Sep 10, 2011)

Wirenuting said:


> Here we don't install the cutout relays. Here we run to destruction. Once a pump kicks on you have to manually secure it.
> 
> And we also call that bypass loop the test loop. Your right about no flow burning out the seals and bearings. She gets hot real quick when the loop is closed by mistake.
> 
> We had one starter here that had the resister bank. I swung by that building today and it's gone. I'll search more tomorrow.


Sorry about that... Kinda went off from fire system pumps to centrifugal pumps in general! Of course I realize that a fire pump is to run until it burns up or is manually secured. My concern was that the folks that build these systems usually have it down to a science. I just have a feeling someone might get bit on the backside here. You can unload any pump by reducing flow, and the op's pump just looks like it is overloaded from the get-go. I don't really think the problem is with the motor, but the pump itself.


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## Wirenuting (Sep 12, 2010)

jmsmith said:


> Sorry about that... Kinda went off from fire system pumps to centrifugal pumps in general! Of course I realize that a fire pump is to run until it burns up or is manually secured. My concern was that the folks that build these systems usually have it down to a science. I just have a feeling someone might get bit on the backside here. You can unload any pump by reducing flow, and the op's pump just looks like it is overloaded from the get-go. I don't really think the problem is with the motor, but the pump itself.


And here I was beginning to think the rest of the world controlled their pumps better or more modern like. 

We have deep pockets so we can afford to destroy stuff. 

Could you spare a little change? I'm only $15,000,000,000,000 this budget year. :-(


<just kidding about the modern world statement.>


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## jmsmith (Sep 10, 2011)

Wirenuting said:


> And here I was beginning to think the rest of the world controlled their pumps better or more modern like.
> 
> We have deep pockets so we can afford to destroy stuff.
> 
> ...


NP... After all, all those savings just blown somewhere else!!!
:blink::laughing::blink:


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## Southeast Power (Jan 18, 2009)

Sorry to resurrect an old thread but, the fire department will be coming out to the building for an "official" test today. I will post the results. I think we all know the answer.


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## Southeast Power (Jan 18, 2009)

*Conclusion (not)*



JRaef said:


> You seemed to have missed the fact that in post #35 the OP said he determined that the problem was indeed the excess flow from the valve being too wide open.


The original motor was removed and sent out to be tested. As we all suspected, It was just fine.

The fire sprinkler company came out again and tested it. Same test of opening the 2" valve on the 6" pipe located on the top of the 12 story building. High amperage again..

They ignore my insistence on a test using a flow meter to see how much GPM we could achieve at the motor FLA.

They decide to buy and install a new motor.

The new motor arrives. I couldn't be there so someone else installed it. They bought a motor with start and run leads.

From what I understand, they connected configured as a WYE and tested it. OOPS.
Then they connected it DELTA. They said that it seems to work just fine with the resister bank start built into the fire pump controller.

Another flow test was scheduled. 
Again, no flow meter, the guy just cranks open the valve 12 stories up on the roof. 
Guess what? The same high amperage reading.

So my question is this guys:
Would I expect this motor to be OK operating on the run configuration using the reduced voltage resister bank start provided by the fire pump controller? 

If so,
I plan to approach the owner with a proposal to measure the water flow from the first floor, 6th floor and roof at the FLA of the motor and have an engineer determine if the GPM is proper for the building sprinkler system.


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## Big John (May 23, 2010)

jrannis said:


> ...Would I expect this motor to be OK operating on the run configuration using the reduced voltage resister bank start provided by the fire pump controller...?


 The few times I've worked on resistor start banks they were very intermittent duty and would quickly get cherry hot or else cutout on high-temp limits if they were left in service, so no I don't believe you can run the pump through them continuously.

I need to re-read the thread. A lot of new and useful information in this one. :thumbsup:

-John


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## JRaef (Mar 23, 2009)

If you have 6 leads going to the motor, as you describe the "start and run leads", that means you have a wye delta starter. If you also have a resistor bank, that means you have a very specialize and somewhat rate version called a " closed transition wye delta starter". There is no difference in the motor, just the starter. Nothing about this should have anything to do with it drawing high amperage. It's still a matter of flow and power.


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## Southeast Power (Jan 18, 2009)

Big John said:


> The few times I've worked on resistor start banks they were very intermittent duty and would quickly get cherry hot or else cutout on high-temp limits if they were left in service, so no I don't believe you can run the pump through them continuously.
> 
> I need to re-read the thread. A lot of new and useful information in this one. :thumbsup:
> 
> -John


The resister contactor drops out very quick.


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## Southeast Power (Jan 18, 2009)

JRaef said:


> If you have 6 leads going to the motor, as you describe the "start and run leads", that means you have a wye delta starter. If you also have a resistor bank, that means you have a very specialize and somewhat rate version called a " closed transition wye delta starter". There is no difference in the motor, just the starter. Nothing about this should have anything to do with it drawing high amperage. It's still a matter of flow and power.


The output of the controller is three wire. No connection for Wye Start Delta Run.


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## MDShunk (Jan 7, 2007)

I know this one is solved, but for conversation's sake, I've seen fire pump motors installed where the installer that changed the motor moved the impeller clearances. There are some models (usually smallish ones) that rely on the position that the hollow impeller stub shaft is bolted on the motor shaft to get the impeller front and back clearances. Not getting this right can cause excessive shaft leakage, or an impeller that's grinding on the front or back pump housing.


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## MDShunk (Jan 7, 2007)

I know this one is solved, but for conversation's sake, I've seen fire pump motors installed where the installer that changed the motor moved the impeller clearances. There are some models (usually smallish ones) that rely on the position that the hollow impeller stub shaft is bolted on the motor shaft to get the impeller front and back clearances. Not getting this right can cause excessive shaft leakage, or an impeller that's grinding on the front or back pump housing.


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## Southeast Power (Jan 18, 2009)

Ok folks, we have an answer. 
I had the fire sprinkler guys open the valve until we had our 167 amps. They gave me a value of 6 psi. 
It worked out to a certain gpm that was ok but not 300% of what we needed.

I brought in my EE buddy that spent much of his younger days in a sugar mill in Cuba. He spent 10minutes looking around and announced that it was the pump. This was about two months ago.
Yesterday, I got a call that the fire sprinkler contractor was going to inspect the pump head. I tagged along.

They opened the top of the pump and it was very obvious that the impeller was installed backwards.
For all of you that kept beating the drum for the mechanical side of the pump package, congratulations, you nailed it! :thumbsup:


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## jmsmith (Sep 10, 2011)

jrannis said:


> Ok folks, we have an answer.
> I had the fire sprinkler guys open the valve until we had our 167 amps. They gave me a value of 6 psi.
> It worked out to a certain gpm that was ok but not 300% of what we needed.
> 
> ...


As long as it took to finally get your answer, I'm glad you didn't have any major fires in the meantime! Have a good day...
-Jim


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## Southeast Power (Jan 18, 2009)

jmsmith said:


> As long as it took to finally get your answer, I'm glad you didn't have any major fires in the meantime! Have a good day...
> -Jim


They seemed to have enough city pressure for one or two apartments plus maybe another 6 or so with the hobbled pump. Major fire, nope. Someone would have been strung up for that pump problem


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## BBQ (Nov 16, 2010)

jrannis said:


> Ok folks, we have an answer.


Cool, thanks for the follow up! 




> They opened the top of the pump and it was very obvious that the impeller was installed backwards.



Pfffttt , probably a union made pump. 












:laughing::laughing::laughing:

Kidding, just kidding ......... really thanks for letting us know what happened.


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## jmsmith (Sep 10, 2011)

jrannis said:


> They seemed to have enough city pressure for one or two apartments plus maybe another 6 or so with the hobbled pump. Major fire, nope. Someone would have been strung up for that pump problem


Thanks for the update.... Like it when a plan comes together! Have a good day.
-Jim


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## frenchelectrican (Mar 15, 2007)

Wowie a backward impeller that cause a alot of headaches.,,,

Merci for posting the following up with the situation and hope other peoples learn from this lesson to advoid the same freaking mistake which it can cost them a cerfication approval.

Merci,
Marc


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