ADDING 25KW SINGLE PHASE TRANSFORMER TO MEP-005A

[edemoss]

we have an RO that is powered by a 005a to supply water in disaster situations. without changing the wiring to the generator can we add a single-phase transformer ( ACME T2535183S primary 240x480 secondary 120/240 25kva ) to supply single phase power for emergency use. we would not run both at the same time and have a circuit breaker box to protect circuits. would it affect the monitoring of generator and if so what would we need to do to be able to run the RO for water separately from supplying single phase. again not at the same time. thanks

 

[Scoobyshep]

assuming you are hooking it up like a normal load, the generator would see it as a load, it shouldnt impact the controls and monitoring.

What specifically are you trying to get out of this?

 

[G744]

Are you trying to step it up to 480V?

Trying to get 240V?

Curious as to what is your target result.

 

[edemoss]

assuming you are hooking it up like a normal load, the generator would see it as a load, it shouldnt impact the controls and monitoring.

What specifically are you trying to get out of this?

supplying power to other locations like pumping stations or cell sites during amergencies. we are part of Plan Bulldozer in the Midwest. Plan Bulldozer is part of the Heavy Constructors Association the help counties and muncipilities during emergencies.

 

[edemoss]

Are you trying to step it up to 480V?

Trying to get 240V?

Curious as to what is your target result.

single phase power 120/240v ac

 

[edemoss]

supplying power to other locations like pumping stations or cell sites during amergencies. we are part of Plan Bulldozer in the Midwest. Plan Bulldozer is part of the Heavy Constructors Association the help counties and muncipilities during emergencies.

when we looked at the gen drawings it shows that L3 is tied to monitoring system and didnt know if that could cause a problem if we used L1 and L3 or use L1 and L2 to power transformer.

 

[Scoobyshep]

Transformer would be more helpful or you needed 120\240 and 480. If it's just single phase you need you can use 2 legs (add a load to the 3rd leg to balance a bit). This gets you 120\208 which 98% of the time is just fine for 240 devices.

If you really need 120\240 you can use a boost transformer or do a single phase mod.

The mod takes about an hour to complete

 

[G744]

Power transformers have an Impedance factor to deal with, and essentially that is a tax on the current flowing thru them.

You'd be better off at just using the output of the genset as is, with approximately balancing the single-phase load across the legs.

 

[DieselAddict]

Since its a MEP005, no way would I try to use an external transformer when you can do a straight forward modification to get single/split phase out of it directly.

 

[msgjd]

1: I concur with G744,, and you already have everything you need right at the lugs ..

2: Just because it's considered 3-phase output doesn't mean you don't have single-phase at the lugs,, because you certainly do !

3: You will access single-phase 240V by attaching the 1ph load, breaker panel, or fused disconnect to L1-L2,, or,, L2-L3,, or ,, L1-L3 ..
(actual voltage will be 208V)

4: You will access single-phase 120V by attaching to L1-L0,, or,, L2-L0,, or,, L3-L0 ..

5: You will be accessing "240V" (208V actual) 3-phase only when a 3-phase load, such as 3ph motor, is attached to L1, L2, L3 ..

6: NEVER fail to bond (ground) all load-side electrical equipment to L0, and maintain such continuity at all times power is energized

7: Although using a 3-phase transformer in between the genset and the single-phase loads will, in-effect, inherently balance those loads on the genset, it's an inefficient method and a transformer adds additional load to the genset ..

8: A quality clamp-on amprobe to help you balance loads on the phases costs about $3200.00 less than a 25kva transformer

 

[edemoss]

1: I concur with G744,, and you already have everything you need right at the lugs ..

2: Just because it's considered 3-phase output doesn't mean you don't have single-phase at the lugs,, because you certainly do !

3: You will access single-phase 240V by attaching the 1ph load, breaker panel, or fused disconnect to L1-L2,, or,, L2-L3,, or ,, L1-L3 ..

4: You will access single-phase 120V by attaching to L1-L0,, or,, L2-L0,, or,, L3-L0 ..

5: You will be accessing 240V 3-phase only when a 3-phase load, such as 3ph motor, is attached to L1, L2, L3 ..

6: NEVER fail to bond (ground) all load-side electrical equipment to L0, and maintain such continuity at all times power is energized

7: Although using a 3-phase transformer in between the genset and the single-phase loads will, in-effect, inherently balance those loads on the genset, it's an inefficient method and a transformer adds additional load to the genset ..

8: A quality clamp-on amprobe to help you balance loads on the phases costs about $3200.00 less than a 25kva transformer

We know enough to be dangerous. by using 2 legs of the 3 phase for 240 would we be out of phase on the 240 and is that a problem in most cases?

 

[Scoobyshep]

Between 2 legs in this set is 208 NOT 240.

Now in most cases 208 is useable on 240 applications, refer to the nameplate on the loads. you can bump th voltage up slightly but this also raises the leg to ground voltage. so items using the neutral will run higher, so be careful what you adjust.

GROUND GROUND GROUND. L0 is neutral, however it should be jumped to chassis (check as who knows who has been in there) If you are tying this to a building through a transfer switch the bonding gets confusing. Feel free to ask if you are unsure .

 

[edemoss]

Between 2 legs in this set is 208 NOT 240.

Now in most cases 208 is useable on 240 applications, refer to the nameplate on the loads. you can bump th voltage up slightly but this also raises the leg to ground voltage. so items using the neutral will run higher, so be careful what you adjust.

GROUND GROUND GROUND. L0 is neutral, however it should be jumped to chassis (check as who knows who has been in there) If you are tying this to a building through a transfer switch the bonding gets confusing. Feel free to ask if you are unsure .

 

[edemoss]

I am somewhat confused here are some photos from the generator. we want to keep it easy when we set it up to produce RO water . the cable going to the RO from the generator goes to a breaker panel that can be shut off. that allows whatever we tie to the generator lugs will be dead going to the RO. we have 2 grounding rods that attach to the Generator and the RO. for safety.
We mounted the transformer as shown with a board to mount the braker panel from the generator.

I just received a message from a person at INOVA out of Basehor, KS that apparently makes parts for the 005a.
He stated hook transformer primary to 216v any two legs of the generator. hook secondary to 240 volts and set rheostat to 216v . mount voltage meter to secondary output and adjust to 240 volts.

From what msgjd is saying i dont need the transformer and adjust the output to 240v . just mount a breaker panel for single phase.
We want to do the right thing whatever that may be. We REALLY appreciate your all's input

 

[DieselAddict]

Is the RO single phase or 3 phase? How much power does it require?

 

[edemoss]

it is 3 phase and takes about 50 amps but will not be running during the time we want power from generator

 

[DieselAddict]

OK. Modification isn't the best way to go then. Just use 2 of the 3 phases when you are running single/split phase loads and understand your output will be limited to around 10kw.

 

[msgjd]

We know enough to be dangerous. by using 2 legs of the 3 phase for 240 would we be out of phase on the 240 and is that a problem in most cases?

it is no problem at all if you divide the single-phase loads among all three of the phases.. i previously forgot to mention specifically your actual voltage between-phases will be 208V which is not an issue with most 1-phase 240 motors and equipment, just that the amperage draw will increase some

The circuits need to be balanced as closely as possible per phase , else the main breaker will trip out due to an overload on whichever phase has too much load .. "Balancing the load" or "balancing the phases" means to add up the amperage of the equipment you expect to run and assign the branch circuits to the phases in whatever way keeps the total amperage per phase about in the same ballpark as the amperage on the other phases , with the FLA (full load amperage) not exceeding 80% of the genset's main breaker amperage.. You really should consult with an electrical friend or acquaintance

I do not know if having zero load on one of the phases for long-term periods while loading the other two phases for long continuous periods causes any damage to the MEPs .. My shop is wired 3-phase to one of my MEP's for repair/testing of 3ph motors including running the 1ph shop lighting, welder, compressor, etc.. At the same time my residence is wired to two of the lesser-loaded legs to provide backup 240V 1ph (technically 208V)... I have done this for several years with no issue but I don't run the genset for more than a few hours at a time, only as-needed ..

Perhaps someone else here will chime in on whether or not the MEP's can run extended periods with load only on two legs without damage to the alternator .. Again, if you put some load on all three of the phases when you aren't running the 3-phase equipment, you will not have any issue with long-term useage combining 3-phase equip and 1-phase equip on the genset..

The last big genset i installed before retiring from that biz was a Cat 300kw 208V 3-phase head powered by a Cat 3406 .. The mill was off-grid and the genset did not power any transformers .. All the lighting, receptacles, welding outlets, smaller pumps, etc. were 1-phase loads utilizing only one or two of the phases depending voltage needed.. That mill runs 8-hours continuous almost daily on that genset since 2007, and all the single-phase loads are dispursed across all three of the legs as close to balanced as was possible .. The company wanted the 208V 3-phase system instead of a 480V system ..

For the curious, there is such a thing as 240V 3-phase, which is provided by an open-delta connection utilizing two utility transformers instead of the typical bank of three wye-connected (208V 3-ph) .. There are a few utilities that have done this since at least the 1930's to reduce the number (cost) of transformers in the field .. It comes with it's own unique set of phase issues

 

[Scoobyshep]

Running two legs heavily loaded in the third leg with no load is not good for the head. It can cause damage after prolonged to use that way.

Still need it for three phase then do not do the modification if you absolutely need 240 volt and can't live with 208 look up a buck boost transformer

 

[edemoss]

Running two legs heavily loaded in the third leg with no load is not good for the head. It can cause damage after prolonged to use that way.

Still need it for three phase then do not do the modification if you absolutely need 240 volt and can't live with 208 look up a buck boost transformer

I think i have a much better understanding after reading these messages. this has really been helpful and very informative. it sounds like a 3 phase panel might be the best way to balance out the load between the legs. I think the lightbulb came on. that gives me 120 and 240 balancing using the 3 phase. again thank all of you .