2 Phase

[AllCircuitsElectrical]

I am working on a project that has 2 phase... Nothing else is available... Commercial building ...4 stories, elevator, fire pump, resteraunt. Upper floor being convert to apts.

Existing 75 kva 2 phase 120/240 to 3 phase 120/240 for restaurant ...

2 phase to 3 phase for fire pumps 120/240

2 phase 120/240 to 3 phase 120/208 for elevator...


4 taps 100 amp (2 phase) with meters and disconnects for 3 floors and house panel , tap for fire,pumps

Then CT cabinet , 200 amp disconnect for 75 kva transformer to the Resturant ...


I need to add at least 6 meters and disconnects..


I do not like the way the engineer has this spec,d ..there is no room , all the fire pump piping in the way,

There is apox 400/600 amp service 4/0 copper 2 phase ...spec to be upgraded to 1000 amp with new disconnect ...(2 phase

 

[AllCircuitsElectrical]

In trying to get a modular solution 2 phase gear is well hard to get. So my idea would be to put all of it thru 1 transformer thus get 120/240 3 phase and then modular meter bank to save space and get all the stuff out of the way...and in an area that has the proper clearances...

Comments please...

 

[zbang]

Can you come in through a couple or three 2-phase service disconnects into Scott-T transformers, then into larger 3-phase (120/208 y) distribution panels? (How much rewiring is going on?)

Oh, and why is the fire pump on the ceiling? :lol:

 

[ActionDave]

I thought you couldn't use a phase converter for a fire pump.

 

[templdl]

I am working on a project that has 2 phase... Nothing else is available... Commercial building ...4 stories, elevator, fire pump, resteraunt. Upper floor being convert to apts.

Existing 75 kva 2 phase 120/240 to 3 phase 120/240 for restaurant ...

2 phase to 3 phase for fire pumps 120/240

2 phase 120/240 to 3 phase 120/208 for elevator...


4 taps 100 amp (2 phase) with meters and disconnects for 3 floors and house panel , tap for fire,pumps

Then CT cabinet , 200 amp disconnect for 75 kva transformer to the Resturant ...


I need to add at least 6 meters and disconnects..


I do not like the way the engineer has this spec,d ..there is no room , all the fire pump piping in the way,

There is apox 400/600 amp service 4/0 copper 2 phase ...spec to be upgraded to 1000 amp with new disconnect ...(2 phase


View attachment 8727 View attachment 8728 View attachment 8729

It has been a few years now but as I recall you must be careful with this as there are both 2ph 4w and 2ph 5w systems which is important when specifying a transformer. As a sales and applications engineer that was one important question that I had to ask in order to have a transformer built correctly.

 

[GoldDigger]

It has been a few years now but as I recall you must be careful with this as there are both 2ph 4w and 2ph 5w systems which is important when specifying a transformer. As a sales and applications engineer that was one important question that I had to ask in order to have a transformer built correctly.

And just because we see only four wires in the fuse box does not prove that there is not a fifth, grounded neutral wire hiding somewhere else.
If it is 2ph 4w, what is feeding 120 volt loads right now? All on transformers?

 

[templdl]

And just because we see only four wires in the fuse box does not prove that there is not a fifth, grounded neutral wire hiding somewhere else.
If it is 2ph 4w, what is feeding 120 volt loads right now? All on transformers?

When taking an order for a 2ph transformer one of the first things that I ask is 4w or 5w. I am not looking to trap my customer into buy a second transformer because they ordered wrong. My responsibility is to look out for them so that the one they order is the correct transformer for their needs. When you often take an order through a distributor lots can be lost between the actual application requirement to those whom are actually placing the order.

 

[GoldDigger]

When taking an order for a 2ph transformer one of the first things that I ask is 4w or 5w. I am not looking to trap my customer into buy a second transformer because they ordered wrong. My responsibility is to look out for them so that the one they order is the correct transformer for their needs. When you often take an order through a distributor lots can be lost between the actual application requirement to those whom are actually placing the order.

What are you generally able to do to get a clear answer when it comes through a third party? Push the question back through them or ask for the information direct from the end user?

 

[hurk27]

I thought you couldn't use a phase converter for a fire pump.

Just a FYI

A two phase to 3 phase converter is a transformer not a phase converter, google a Scott T transformer to understand how you get 3-phase from a 4 or 5 wire two phase system

 

[hurk27]

Oh, and why is the fire pump on the ceiling? :lol:

The same reason the light fixture is on the floor:slaphead:

 

[templdl]

What are you generally able to do to get a clear answer when it comes through a third party? Push the question back through them or ask for the information direct from the end user?

I've done this for some 21 years and have learned the importance of documentation. I try to protect the end unsure the best that I can but you soon learn that there are limits. I have supplied dry type pad mount transformers on many occasions to power the avionics for airport runways such as the 4 transformers that I have on the Island of Guam. Step up from 240v 1ph2w to 600v as I can recall, it may have even be 2300v, then back down to 120/240v 1ph3w. In one instance an engineering firm placed the order with me directly for an airport in Louisiana.They specifically specified 240v 1ph2w for the secondary of the step down transformer. I questioned them numerous times knowing that they would be needing 120v but they insisted that it would be 240v. So that was the way they ordered it and the way that I had it built.
The transformer shipped and then the call came from the contractor, " where is the neutral?"
The engineering got the privilege of reordering the correct core and coil which I had to have modified to match the mounting for the secondary terminations. Sometime you can lead a horse to water but you can't make him drink. I couldn't convince the engineering firm that they should reconsider the secondary voltage.
It must be understood that I had been responsible to the company/distributor placing the order with me and for their errors. However, it is good customer relations to try to interject my concern should I question whether or not the order is being placed correctly.

 

[AllCircuitsElectrical]

thanks ... i do not know why when posting pics from the iPad they come out sometimes upside down when posting ....LOL

i have pics of all the name plates from the transformers ... my supply house tried to lookup the 75kva transformer and it did not come up they said it was special order ...



the engineer on the project wants to leave the 4 100 am disconnects in place and for "us" to extend the trough up to the ceiling across the room ( over the fire pump through the fire pump piping )
into the back area and add 6 meters, and 6 disconnects ...

they want to change the wiring to 600mcm cu, so i would have to tap 10 individual times, plus the fire pump, landing then in the CT and 200 amp disconnect for the 1st floor resturant than is shown.

the 1000 amp disconnect would lower the number of throws to shut off the building ,


5 wire .. 2 for each phase and one neutral ... best i can tell ...

 

[Fulthrotl]

In trying to get a modular solution 2 phase gear is well hard to get. So my idea would be to put all of it thru 1 transformer thus get 120/240 3 phase and then modular meter bank to save space and get all the stuff out of the way...and in an area that has the proper clearances...

Comments please...

looking at the pictures made me grateful you are doing this, and i'm not.
my head hurts. can i go home now?

if you are going to specify a transformer to convert two phase to three phase,
what is your reason for making secondary side 240 three phase instead of 208 3 phase?

 

[AllCircuitsElectrical]

75 kva....

 

[AllCircuitsElectrical]

inside the CT cabnet ....

 

[mgookin]

thanks ... i do not know why when posting pics from the iPad they come out sometimes upside down when posting ....LOL

...

Are you left handed? I hired a sales person 2 months ago and during the first week he sent some pictures & videos. They were all upside down. I told our GM to make him a label for his phone "This end UP". A month after that I saw an e-mail from a customer mocking him for his upside down videos and asked why this was still going on. The next day he says he figured it out - he's left handed and when he rotates the phone, it corrects his display but the camera inside the phone does not compensate for this.

 

[ActionDave]

Just a FYI

A two phase to 3 phase converter is a transformer not a phase converter, google a Scott T transformer to understand how you get 3-phase from a 4 or 5 wire two phase system

Gotcha. When I posted I didn't notice the OP's location is in PA. I mistook two phase as a synonym for single phase.

 

[conmgt]

I am working on a project that has 2 phase... Nothing else is available... Commercial building ...4 stories, elevator, fire pump, resteraunt. Upper floor being convert to apts.

Existing 75 kva 2 phase 120/240 to 3 phase 120/240 for restaurant ...

2 phase to 3 phase for fire pumps 120/240

2 phase 120/240 to 3 phase 120/208 for elevator...


4 taps 100 amp (2 phase) with meters and disconnects for 3 floors and house panel , tap for fire,pumps

Then CT cabinet , 200 amp disconnect for 75 kva transformer to the Resturant ...


I need to add at least 6 meters and disconnects..


I do not like the way the engineer has this spec,d ..there is no room , all the fire pump piping in the way,

There is apox 400/600 amp service 4/0 copper 2 phase ...spec to be upgraded to 1000 amp with new disconnect ...(2 phase

So each floor is one apartment?
1000A ?? For 3 apartments and a restaurant yet the restaurant exists already with the current service. What loads are expected from these apartments?

I think this is over calculated especially in SE PA. I'm sure there's NG serving the restaurant so there wouldn't be much power needed for cooking or heating. And NG heat for the apartments.

Have you seen the calcs? I think that you should look them over.
What town is it in? I'm in Philly.

How about third party metering for the apartments? Then you could put the meters next to the subpanels in each apartment.