# Delta 4 wire



## Southeast Power (Jan 18, 2009)

This is absolutely the best application for this type of service.
The best way to set it up is to put the new service ahead of the old one and use the new three phase service to feed the existing single phase panel.
This will keep non electricians from getting into the high leg.


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## BBQ (Nov 16, 2010)

Not even an option here.


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## erics37 (May 7, 2009)

Our power company won't even install a new Delta service.


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## hardworkingstiff (Jan 22, 2007)

Do you have any existing 240 loads that might have to be rewired for 208? Like multi-tap ballast, AC equipment (yes I know most of them are rated 208-230), etc.


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## denny3992 (Jul 12, 2010)

I redid a 240d at the local vfw and i brought it into a trough inside and tapped a 3ph disco off for the only 3ph load (chiller) and installed a 40circ 1ph panel for all other loads!

Seemed like the best thing to do!


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## erics37 (May 7, 2009)

denny3992 said:


> I redid a 240d at the local vfw and i brought it into a trough inside and tapped a 3ph disco off for the only 3ph load (chiller) and installed a 40circ 1ph panel for all other loads!
> 
> Seemed like the best thing to do!


A local shipping depot is like that. They wanted to replace a reversing starter for their conveyor belt one day, and I was like WTF, you have single phase service. Then I looked more closely and realized that simply because I had never gotten into the 3-phase disco didn't mean it wasn't there :laughing:


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## Big John (May 23, 2010)

If you can get it, it'd be perfect. Never seen a new high leg service. All of them are either private transformers or decades old.


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## Honestly (Feb 3, 2011)

Why don't they do them anymore where y'all are? I mentioned it to the poco engineer in passing and he acted fine with it, just said submit it in writing.


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## Southeast Power (Jan 18, 2009)

The marina next to the job I'm on just had an open delta installed. Two pots on a pole.
Very common here.


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## hardworkingstiff (Jan 22, 2007)

jrannis said:


> The marina next to the job I'm on just had an open delta installed. Two pots on a pole.
> Very common here.


That is a great idea for marinas.


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## micromind (Aug 11, 2007)

Honestly said:


> I am considering going with a Delta 4 wire service on a retrofit (existing 1Ph to new 3Ph). The only load is a 50hp pump, and a light and receptacle. Poco had spec'd a 208 Y, but 240 rather than 208 would allow a size 4 starter instead of a size 5, saving the customer some $. I have never requested a Delta service before- any extra expense or complication that I am overlooking?


If the POCO will supply a 240 ∆, this might be the best way to go. 

Another option would be a 480 service (it could be a wye, 4 wire ∆, or 3 wire grounded B), and install a single phase transformer to supply the 120 loads. This way, you'd need a size 3 starter and a fused disconnect switch for the transformer primary. 

This would very likely cost less than the difference between a size 3 and a size 5 starter, plus you'd be connecting the motor with #4s instead of 2/0s.


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## Jlarson (Jun 28, 2009)

We'd almost always go 480 for a 50 hp.


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## Honestly (Feb 3, 2011)

That was the original plan, but due to the fact that all operation and maintenance will be done by "unqualified" personnel, I thought 240 would be a little safer... Reduced risk of arc flash and all


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## Meadow (Jan 14, 2011)

Honestly said:


> Why don't they do them anymore where y'all are? I mentioned it to the poco engineer in passing and he acted fine with it, just said submit it in writing.


A combination of standardization/cost (single bushing transformers are cheaper over double) and fears of ferroresonance .


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