# Crane Control Cabinet A/C 180F Ambient



## Navyguy

Although not specific to your situation, I have relocated cabinets on cranes to a less harsh environment. I know some of the cabinets would be tough to move / rebuild depending on the design of the crane. It may also require some safety approvals.

The other option is to increase the cabinet size and add a separate cooling unit such as CO burst or AC unit. Fans will not work because you are just drawing the hot air across the contacts and likely contaminants.

Cheers
John


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## telsa

At those temperatures I'd suspect that you're going to have to install some active cooling -- as in chilled water with anti-freeze. 

Sounds like a real project.


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## splatz

The vortex coolers are supposed to be the best in high ambient temperatures, but is it possible to get compressed air up there?


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## al_smelter

Relocation would be a tough prospect in that there are few, if any areas on board the crane that are not susceptible to the high temps. It would also require a fairly lengthy outage. This thing runs 24-7. Just getting time to PM it is like pulling teeth with no anesthetic. 

I am not familiar with CO burst, though just from its name it sounds intriguing. Would you know offhand an information source on this? I'll Google it as well.

I'm in process of researching a vortex cooler. I would need to install an on board compressor with more than 8SCFM capability. Then all I would need to know is the life span of the compressor in those temperatures.

While off on one of my daydreaming sessions after I wrote this it occurred to me that both of our cab operated 210 ton cranes have cooling for both operator and drive cabinets. I'll be looking into that this morning to see what they have onboard that can withstand oven-like temperatures.

Good conversation guys. I'm sure there is a way that is safe, effective and economical. We'll find it sooner or later.

Cheers,


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## John Valdes

Is the control cabinet on the bridge?
I worked in a very hot plant for some time. Not anywhere as hot as your plant is.
We used AC's on each panel and we were constantly working on them.
Finally we subbed out these AC's to our HVAC guys.

Once they realized they were spinning their wheels, they got a bright idea and mounted AC units on the roof and ran insulated duct work to any cabinet that needed cooling.
They were designed so when the ambient air outside was cold enough, the AC's would shut off and the blowers would pull in outside cold air.

They worked very well and when you opened a cabinet it felt so nice and cool. But it was not as hot as your plant Al. Not close to being that hot.


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## al_smelter

Yeah John, these cabinets are on the moving bridge. From what I'm told, this crane is by far the least reliable of all of our bridge cranes. The reason is two fold. First, we stack cherry red hot slabs 12 or so high, which leaves no more than 10-12 feet of air space between the stack and the crane bridge. Second, the ceiling isn't nearly high enough (we can replace high bay lights from the bridge platform), which allows the accumulated heat to pile up in right smack on the bridge. I'm told that in July the bridge platform will actually burn blisters on your knees if you kneel down to get in the control cabinets. You also cannot touch any metal parts without welding gloves. Kinda hard to change tips on contactors don't ya think?! I honestly don't know how the damn thing works at all in the summer.

The guys go on calls in threes and rotate five minutes with two standing at the outside door while one goes in to work. How efficient is that?!

As well as pursuing some sort of internal cooling, I'm going to recommend removal of the uppermost exterior wall panels along the slab bay to allow some of the trapped air to escape. At this point it's either that or rack up a hellufalot of delay minutes this summer. I know what I'd choose!


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## JRaef

I had a similar issue with crane controls over an aluminum pot line. We tried the vortex coolers, they didn't work reliable PLUS, they took *100*CFM at 40PSI, which translated to about 7-1/2HP worth of compressor power because you also need it to be very very dry and oil free, otherwise you kill the electrical equipment and the dryer and oil filters robbed a lot of compressor power. We never even entertained the idea of mounting the compressor on the crane, it would require too much maintenance and besides, I too think it would be too hot up there for the compressor.


We settled on Thermoelectric (Peltier effect) coolers which were new at that time and added serious rigid foam insulation to the walls of the enclosures, which meant rebuilding the cabinets to make room for it. The TCA (Thermoelectric Cooling Assembly) coolers were very expensive but rated for 70C operation (158F), mostly because that is the upper limit of even military grade electronics. I was associated with that aluminum mill for about 9 more years after putting those in, I never got a single complaint. Unfortunately the company that made the coolers is now gone, probably eaten up by someone else, but there are numerous TCA manufacturers out there. You could talk to some of them.


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## al_smelter

JRaef said:


> I had a similar issue with crane controls over an aluminum pot line. We tried the vortex coolers, they didn't work reliable PLUS, they took *100*CFM at 40PSI, which translated to about 7-1/2HP worth of compressor power because you also need it to be very very dry and oil free, otherwise you kill the electrical equipment and the dryer and oil filters robbed a lot of compressor power. We never even entertained the idea of mounting the compressor on the crane, it would require too much maintenance and besides, I too think it would be too hot up there for the compressor.
> 
> 
> We settled on Thermoelectric (Peltier effect) coolers which were new at that time and added serious rigid foam insulation to the walls of the enclosures, which meant rebuilding the cabinets to make room for it. The TCA (Thermoelectric Cooling Assembly) coolers were very expensive but rated for 70C operation (158F), mostly because that is the upper limit of even military grade electronics. I was associated with that aluminum mill for about 9 more years after putting those in, I never got a single complaint. Unfortunately the company that made the coolers is now gone, probably eaten up by someone else, but there are numerous TCA manufacturers out there. You could talk to some of them.


After a hellufalot of research and head scratching, I have come to the same conclusion. I put a call into ISC Sales late yesterday afternoon, who either manufactures or distributes Delta-T enclosure coolers. The engineers are running my numbers now to see what they can come up with. Hope it doesn't crash their sizing calculator!

One thing to keep in mind is that this heat load is not necessarily 24-7. The ambient does go down slightly at night, and summer storms or stiff breezes sometimes carry away some of the heat. However the temps are still way too high to maintain reliable controls. I'm aware that any heat exchanger type of unit will cease to function in our most extreme conditions; that's the nature of the beast. But if I can get the internal temperatures down to a reasonable level for a majority of the time, it'll still be a win.

Stand by folks. And thanks for your suggestions.

Mark


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## Navyguy

Where we could we always moved the boxes to the floor or off to the side of the bridge when possible as out first option.

The CO2 blast that I mentioned were home make jobbies… essentially you are connecting a CO2 line to the box and it gave a short blast every so often. We used CO2 vice standard air simply for the cooling effect, plus it is dry and clean.

The first one we did we put insulation on the exterior, and it melted almost right away… pretty stupid after we thought about it…

The second one we gave that a bit more thought; we put insulation on the inside and incorporated a pressured drain / relief on the bottom. This worked good as an initial concept, but then we had to consider how much CO2 to blast in there, at what intervals, etc. We also had to incorporate some sort of failsafe on the CO2 line because if it started to leak or broke we could not afford to let CO2 run undetected as it is quite expensive.

We continued to build on this one and incorporated the changes / upgrades into a third one. In that situation we included a cable along with the CO2 line so we could put in a moisture sensor and temperature sensor. These were hugely expensive projects in the end, but like a majority of plant work, the people are there anyway and most liked the project stuff.

A nuber of points, we found that the larger box was better for the equipment because the CO2 did not blow directly on the components. There was a bit of condensation that formed, so by having the larger box, the condensation tended to stay close to the insulation. You had to have enough pressure to open the drain but and move the condensation, but not so much that it changed the shape of the door / cover or put pressure on the cover seals. We had to add some stuff to the LOTO for the pressured line going into the box. There was also some issue with the crane manufacturer and some “safety” regulations as we were modifying a “lifting device”… but quite frankly I don’t know what the end result was. That was just not the CO, but the fact that we were relocating crane controllers all over the plant for better maintenance and life span.

Than plant shut down and razed a number of years ago and I have no idea how long our “CO blast” lasted. I would say it made a difference, but it is hard to tell if it was the CO blast that made a difference or the simple rebuilding of the box and components.

Cheers
John


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## JRaef

Where did the CO2 come from, bottles?


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## telsa

I'd be shocked if Peltier effect (solid state electronics) coolers can tolerate the temperature.

That puppy is running so hot that you are, in effect, cooling a motor.

You know you're going to want to insulate it every which way and then provide active cooling.

It's so hot I can't see how you can avoid water + antifreeze as the circulating medium. 

At least that's a low pressure solution with tons of engineering data to go by. Obviously you'll have to locate the heat exchanger at the bottom of the cabinet and have a warning circuit for any leakage. I see it running all the time.

Down low I can imagine an active refrigerator -- pulling the coolant down to, say, 100F.

It won't have to be big, as the heat load that gets though your insulation should not be staggering.

What ever it is, it'll have to be industrial strength -- with alarms so that you can jump on things before they get out of hand.


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## John Valdes

You do have exhaust fans right? Roof exhaust fans?


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## Navyguy

JRaef said:


> Where did the CO2 come from, bottles?


Large storage tank. We used it for other instrumentation instead of compressed air.

Cheers
John


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## splatz

https://www.eicsolutions.com/high-ambient/


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## telsa

190F -- that's amazing.


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## JRaef

splatz said:


> https://www.eicsolutions.com/high-ambient/


Ah! That's the one I used way back when, it was called ThermoTec back then, which I see is now their registered brand name, so this must be who "gobbled them up".


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## al_smelter

splatz said:


> https://www.eicsolutions.com/high-ambient/


I'd been all over the EIC website, or so I thought, but never ran into this page. I will contact their engineers to find out how they get their magic to work. I have certainly seen no other claims by anyone else to meet that ambient spec.

Many thanks.

We have access to argon and nitrogen on site, but not CO2. However, The concept is still worth contemplating. Would have to figure out the safety aspect of compressed gas tanks on an overhead crane with high heat and high vibrations. 

Mark


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## Navyguy

Our tanks were like this but vertical...









We just tapped off the main header and ran flexible braided hose to the bridge.

Cheers
John


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## Bird dog

al_smelter said:


> First, we stack cherry red hot slabs 12 or so high,


Was it designed for 12 or did someone get the bright idea to stack them 12 high rather than eight or ten?


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## al_smelter

Bird dog said:


> Was it designed for 12 or did someone get the bright idea to stack them 12 high rather than eight or ten?


Absolutely not; the entire complex was not meant to function the way it does. But, as with almost everything industrial, functions change. I have rarely seen a facility that was thought out, designed and built with what was going to happen thirty years down the road.

This plant started out as simply a 60" hot strip mill. The target customer was for small custom orders. You wanted six coils, you ordered six coils from us. US Steel would only sell you six hundred coils. So, slabs were imported back then from wherever and rolled to customer spec. And, naturally, they arrived cold. The "warehouse was X feet high and designed to hold X number of slabs. Slabs were inserted into a re-heat furnace and rolled. Then someone along the line got a bright idea to make slabs on-site. And the board of directors concurred!

The melt shop was added only ten years or so ago, and the super tall EAF (electric arc furnace), LRF (ladle refining furnace, also electric arc) and casting bay were tacked on to the side of the warehouse. So, by design the caster runout table ended in the lower, former warehouse bay, and the existing cold slab handler crane became a hot slab handler crane.

Easy to see the shortcomings of the design. No exhaust fans in the lower bay ceiling- weren't needed. Increased slab making insured the need for taller stacks of product- ran out of space. A twenty foot high stack of 8" thick slabs will retain much heat for weeks. Slabs directly out of the caster are just south enough of molten to retain their shape. And the list goes on. It's a recipe for cooking anything hanging in the ceiling. I just happen to have frying crane controls in that damn low ceiling. 

Still waiting on a callback from EIC. Hope they can come up with a solution. Still going to recommend peeling some of the siding off during the summer. Might mention exhaust fans, but that would be a huge expense to ventilate such a huge area.

Oh well, why I get the big bucks, right? Come up with a solution. Workin on it!


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## Bird dog

al_smelter said:


> It's a recipe for cooking anything hanging in the ceiling. I just happen to have frying crane controls in that damn low ceiling.


 This isn't my wheelhouse, but, it sounds like you may need a engineer (process engineer?). If the steel holds its heat, then by all means cool the place down. Even in the Middle East they only design gensets for 30-50 degrees Centrigrade (not even near 200degrees F).


Edit 90-120 degrees F is 30-50 degrees C


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## MikeFL

30 minutes down the road!

Make it work. Make money. That's why we're here. Gitter done!


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## MikeFL

30 minutes down the road!

Make it work. Make money. That's why we're here. Gitter done!


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## Bird dog

MikeFL said:


> 30 minutes down the road!
> 
> Make it work. Make money. That's why we're here. Gitter done!


The management "what do you mean you can't get blood out of a turnip?" :surprise:


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## al_smelter

For inquiring minds that want to know, here's a quick update on the EIC cooling solution:

Their lead engineer wrote me back the nicest letter... and stated that no, they cannot cool with 80c (176F) ambient, and they certainly cannot cool at 87.4c (190.04F) as stated on their web page. They can cool to 70c (158F). Well, from my exhaustive research so can everyone else.

I have replied back to her with a link to their website and asked her what the text on that web page REALLY means (I suspect she will be done with me!). I am now curious as to what happens to a Peltier effect device when the ambient goes out of range. Will it simply cease to provide any cooling or can it damage the unit? I would think that it would just fail to provide any heat exchange. The things aren't terribly efficient anyway.

So, folks, the magic show didn't happen; we're going to have to change tack. Maybe a duct from the building wall to the cabinet and a simple fan. 90F through a 40 foot insulated duct would still reach the cabinet at well below 180F.


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## MikeFL

From your first post it sounds like you have multiple cabinets to cool.

They should invest in a good HVAC engineer to develop this system. One thing that comes to mind since you said pulling in rooftop air is an option to consider, is to install a RTU and draw in outside air and cool it (by 20F or whatever it will cool it by) and feed a manifold which feeds cool air to the cabinets. At least you won't be trying to work with 175F air.


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## al_smelter

If the almighty powers will allow me to yank the uppermost sheet metal siding off the building (about 800 feet), or at least every other sheet, then any number of solutions might be feasible, including an RTU off to the side. That is exactly how our two 210 ton melt cranes are cooled, though the melt side is not quite as hot because it has a particulate extraction system over both furnaces. It brings in a goodly amount of outside makeup air to feed the baghouse dust collector.

Still workin on it.


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## John Valdes

Do you have roof ventilation fans?


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## telsa

I thought 190F was out of range!


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## al_smelter

John, there are no roof vent fans at this time. We might consider a couple of downdraft fans over the parking spot of the crane and the slab runout table. Yes, the temperature 600 feet down the bay would still be abnormal, but even a slight cooldown when back home should help. The space is too vast to ventilate the entire building. Up front costs of retrofitting forced exhaust would almost certainly be cost prohibitive. We have to weigh the cost balance between crane failure modes/ downtime versus capital or maintenance engineering expenditures. I do not know what that balance is yet, but I am actively tracking temperatures, crane downtime, and repair parts/ labor costs.

Telsa, I'm not sure I understand your last post. Indeed 190F ambient seems to be absolutely out of range for any type of (feasible) point of use cooling technology available today, and especially for a machine that travels close to a quarter mile each way hour after hour. 

The list of solutions is shrinking, and may come down to either ducting outside air to the cabinetry, which might get temperatures to 125+ in the enclosure, or to install a conventional compressor based air conditioning unit with its makeup air close to an outside air source, then ducting (much) cooler air to the equipment.

More to come.


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## Bird dog

al_smelter said:


> John, there are no roof vent fans at this time. We might consider a couple of downdraft fans over the parking spot of the crane and the slab runout table. Yes, the temperature 600 feet down the bay would still be abnormal, but even a slight cooldown when back home should help. The space is too vast to ventilate the entire building. Up front costs of retrofitting forced exhaust would almost certainly be cost prohibitive. We have to weigh the cost balance between crane failure modes/ downtime versus capital or maintenance engineering expenditures. I do not know what that balance is yet, but I am actively tracking temperatures, crane downtime, and repair parts/ labor costs.
> 
> Telsa, I'm not sure I understand your last post. Indeed 190F ambient seems to be absolutely out of range for any type of (feasible) point of use cooling technology available today, and especially for a machine that travels close to a quarter mile each way hour after hour.
> 
> The list of solutions is shrinking, and may come down to either ducting outside air to the cabinetry, which might get temperatures to 125+ in the enclosure, or to install a conventional compressor based air conditioning unit with its makeup air close to an outside air source, then ducting (much) cooler air to the equipment.
> 
> More to come.


How do other foundries address this problem?
Or, how does your competition do this process?


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## al_smelter

Most other facilities are purpose built for the hot environment. The most common type I'm familiar with is the ridge roof vent system. You start with a common gable style pitched roof. A smaller louvered peak ridge roof then runs the length of the building and its design creates an inherent draft from bottom to top. I'm sure there are other types of natural ventilation types as well.

The other thing they do is to make the roof high enough to put the bridge rails closer to the center of the building in elevation. This lets the hot air pile up in the peak but leaves the cranes below the hottest area. This is the kind of environment for Peltier cooling, or sometimes simply a couple of filtered fans.

Our flat roof steel building was fine for its initial design when the products were moved around cold. The mistake when designing for expansion was failure to consider the addition of superheat in a low bay environment. Now they either have to live with it or spend a $hit-ton of money to fix it. I'll give them several options with costs, and then we'll see just how badly they want it rectified.


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## al_smelter

Well, I’ve beat my head against the wall for some weeks now, and I think I may have a shot at a solution, or at least a band-aid. However, I could use another opinion or two. I’ll explain:

There appears to be no magic machine available to drop the temperature inside the cabinets. Nothing short of space station equipment can survive the high ambients inside the building. All my A/C engineering contacts have either blocked me or changed their e-mail addresses!

I measured 179F this morning on the cabinet door front with a non contact IR thermometer; too hot to touch bare handed (1000 hrs, inside air ambient 159F, outdoor air ambient 68F @ 64% RH). I measured 149F at the furthest east bridge structure, just beside the man entry door. So, my thoughts are:

1.) I have persuaded the ones- we- bow- to to allow removal of the upper wall section sheet metal on the east side of the building, at least a couple hundred feet of it anyway.

2.) I will be having quotes from our resident HVAC company to install 8” double wall insulated spiral ducting along the upper bridge structure, 30 feet from the cabinet to as close as possible to the east wall without dinging it on columns. There will be a replaceable filter and rain hood at the east intake.

https://www.spiralmfg.com/high-pressure-dual-wall-insulated-spiral-pipe/

3.) I’m pondering an 8” Coppus blower (probably the Cadet) installed several feet from the intake.

http://escosalesco.com/PDF/DresserrandCOPPUScatalog2015.pdf

There would be an 8” duct opening cut into the upper east side of the enclosure and an 8” exhaust hole with slide gate and louvers cut into the lower west side. The blower would (might) be thermostatically controlled but would run continuously throughout the summer. So, here’s where I need thinkers.

I am concerned about condensation during temperature and humidity shifts in the weather (from where the air will be drawn). In the dead heat of summer, I don’t think it’d be a huge problem, but transitions in weather in early spring and fall could have some wild swings, both in temperature and humidity. Do we think that 6-800 CFM of (somewhat) cooler air rolling around in a hotbox full of relays and radio transmitters could become a condensation issue? Should I look at less air movement? If 800 CFM is too much for a 36”x36”x12”, should I send some of the excess air to the contactor cabinets?

I can get at least a 20-30F degree delta T just by forcing in air from 30 feet away, and could even get a bonus if pulling the siding off allows outside air to mingle at the intake. But I damn sure don’t want to drown my electronics in the process.

As usual, all opinions are welcome, except giving this project to someone else! Would love to, but still must earn my tenure.

Regards,
Mark


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## MikeFL

With the humidity in the air and the temperature differentials you may indeed get some rain in that box. How about a fan speed control? Once you determine best practices for airflow vs. relative humidity maybe incorporate a humidistat to control fan speed.

Sounds like you're on to as best as can be expected given the circumstances.


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## splatz

I thought you'd only get condensation on the cooler side of the temperature differential, if 150 degree warm humid are comes into a 175 degree cabinet you won't get condensation. You get condensation on a cold glass of water not a hot cup of coffee.


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## scotch

Do a search on ammonia absorption units...I know some overseas telecoms were using these units for telecomm cooling in remote areas ; Australia comes to mind , with no power available for standard cooling units.
Same principle as the 3-way style of refrigerator in campers etc.


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## al_smelter

Just a quick update to this thread- I bought and installed an 8" Coppus type blower and located it at the farthest east edge of the bridge (where the siding panels have been removed). I put a K&N air automotive air filter on the intake side, and a 25 foot flexible duct on the exhaust side along the bridge girder to a cut hole in the radio panel. I also installed a filtered louver on the opposite side of the cabinet (to prevent backflow debris if the fan shuts down).

My remote thermometers have told me that at the least we have lowered the internal temperature by 20- 25F (the heat load of the cabinet and a little bit more). We (the electricians) have had no calls to the crane since last Friday for heat related failures. Prior to Friday we were averaging about one call per shift for radio failures. All the guys were doing was opening the cabinet door and letting the electronics cool down for twenty minutes.

So, from my shift reports, and a couple of craftsmen comments, it appears that the electronics are being cooled at least enough to keep functioning. It's still hotter than I wanted, but we are limited for solutions due to the hostile environment. I bought cheap parts and pieces as this is just a proof of concept, but will enhance the install if it proves to be successful for prolonged duration (better fan, insulated ductwork, etc.). It's been hotter than the hinges of hell here and will be around 100F for the next few days. If The crane doesn't go down today or tomorrow, I'll be a seriously happy camper.

Thanks again to all of you who have helped with suggestions and possible solutions. It helps to have other professionals to bounce a few ideas of.

Cheers


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## MikeFL

I'm happy to hear you're on to something that looks positive. And your boss must be happy with the budget.


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