Perplexed by Generator Output

[Desertfabworks]

I have a 25kw Kwiet power DGK25B I got it at salvage with a blown engine. I replaced the engine is original equipment. I really have not used it much other than to test it out. I hook a volt meter up and I get 123 from the 12v sockets and I get 250 from the 240 sockets. Seems acceptable. I checked the HZ and I'm getting 56 Hz from all the outlets. The adjustment wont allow me to go up anymore. I put a plug tester on all the outlets the kind with three lights showing if and outlet is wired wrong. Shows it wired correct.

A local charity asked me if they could use it for their event so I offered it up at no cost to help the community. This is its first big use.

On the Hz not positive but I think I the only way to increase that would be to adjust engine rpm.??? Not positive. feel free to help.

Here is the Perplexor: I hook up a 50 amp twist lock run it to a spider box. I check voltages of the plugs at the spider box with volt meter and with Hz meter all are the same as at the generator and are fine. A guy wants power to his RV so we hook into the spider box on a 120v plug and plug in his RV. Nothing runs no power at the RV. I check with the volt meter 123 volts 55Hz but no power on the RV outlets. Yes I checked the breakers. Now I take the same plug that I was plugging into the spider box and put it into a little honda generator and his trailer comes alive. Pull it out of the honda plug it into the spider box plug which reads wired correct and 123v and nothing?????

How can that be? What am I missing???

 

[Rookie2]

you need to go into the box where the 50amp twist loc is wired to and check the connections, i would hard wire a space heater or something that would draw some amps and check the output at the generator output wiring.

Is there more than one wire to the injection pump ? If there is then it may have an electronic governor if its one wire solenoid type then you will have jack screws to set RPM.

 

[Desertfabworks]

You would think that since I'm getting 123v and 55Hz t the spider box and the outlet check plug says it is wired correct everything would work fine.

I found that when I plug in a large florescent fixture to the two 120v outlets on the generator the light lights up bright and fine.

When I plug the same light into the spider box the light barely comes on and flickers. Despite the plug saying 123v and 55Hz. What type of wire problem would cause this?

And is it likely at the generator 50a twistlocks or at the spider box?

 

[Rookie2]

Start at the spider box and take a look inside then work back to the plug then receptacle. could be a bad connection.

 

[GMBracing]

measure your voltage under load, the spider box could have a flakey connection. when you draw current the voltage drops

 

[Rookie2]

I'm wondering if it has a (rotary) voltage changeover switch on it ? or is it hard wired for 1phase ?

 

[rockwithjason]

Engine rpm must go up to raise frequency. Adjust the throttle linkage until its within 0.1 hz.
Check the 50 cords for open neutrals. CHeck the main bonding jumper at the gen too

 

[wyliesdiesels]

To achieve 60hz output, the engine rpm must be a multiple of 900rpms, aka 1800 or 3600 RPMs...

 

[Desertfabworks]

Thanks for all of the input.

I checked the spider box and all of my connections are tight. I can not find anything wrong with anything in the spider box.

I pulled apart the cord running from the generator to the spider box. I noticed that my gen 50 amp hubbell outlet has 4 wires. My spider box is set up on the hubbell connections with 4 wires. My cord is a 6/3 soow Would that make a difference?

The 50 amp connections on the spider box have a ground that is just attached to the ground screw on the box since we do not have a traditional earth ground like a house.

 

[Desertfabworks]

OK so let me see if this is the problem. The cord is a 6/3 and is set up with two hots using the black and white wire. The green is still ground.

That comes from the generator to the spider box. When it gets to the spider box my green ground connects to the ground on the box. My black goes to black my white goes to my red line in the box. I have no white (neutral) going into the box.

But I do get a reading of 120 out of my 120 outlets and 250 out of my 250's.

On the RPM's on the engine I will adjust that and see how my Hz does.

 

[RPH]

No neutral? Should be a four wire circuit. Two hots, neutral, and the ground. 240 vac between the hots and 120 vac between one hot and the neutral.

 

[Desertfabworks]

The generator is a 4 wire circuit and so is the spider box. Guess I got a bad cord you thing for $300 with the 50amp hubble connectors it would have been all correct. Its 100feet of 6/3 not 6/4 like I thought.

So my cord only has 3 wires not 4. The cord is running two hot legs and a ground. Since with generators there really is not an earth ground.

Could I take my two hots red and black and turn my green into a white (neutral)?? Would that work or would that be too much of an electrical no no.

Do I need to bite the bullet and get a 6/4 cord?

 

[mshell56118]

You should have a true ground on the generator aka ground rod in ground and hooked to ground connection on generator. You could get away with using your 6/3 as hot hot neutral but then you would need to ground the spider box seperately. It would not be the proper way but has been done. We do it occasionally that way when we are dragging runs of 4/0 cable several hundred feet to keep from pulling that much additional cable


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[C96]

Do it right and get the correct cord with the 4 wires. Don’t try skimping on the ground, it could lead to devastating results

 

[Cmreschke]

Could also just run yourself a green #6 single wire with your 6-3 cord set externally, just get 4 wire receptacles and enter the conductor with the cord. Make the cords green your neutral and your external green becomes ground.
Tape the green to the cord set every 2-3 feet or so to keep it all together. Not the best way of doing it but it would be way better than not having a ground at all. It is for temporary use as well so you should be alright.

 

[CNGsaves]

Do it right and get the correct cord with the 4 wires. Don’t try skimping on the ground, it could lead to devastating results

^ ^ ^ This !!!

Do NOT be "donating" use of this for charity use - - ie risk killing innocent person who could get electrocuted from improper ground . . . UNTIL you know with 100% certainty that genset is working properly AND grounded.

Killing yourself is your decision . . . but do NOT risk others !!

Send a PM to Sewerzuk who is a Genset guru . . . . check out his YouTubes on reviving military gensets. He'll likely set you straight.

 

[Desertfabworks]

Knowing I can do it and doing it are two different things. I appreciate all the help. I will get a new 6/4 cord and re purpose the 6/3 for something else. I'm all about doing things the right, correct and safe way, but I do like to have the knowledge about what will and will not work in my mental file cabinet for when innovation is required.

Thanks again for all the help.

 

[theoldwizard1]

Could I take my two hots red and black and turn my green into a white (neutral)?? Would that work or would that be too much of an electrical no no.

Knowing I can do it and doing it are two different things. I appreciate all the help. I will get a new 6/4 cord and re purpose the 6/3 for something else. I'm all about doing things the right, correct and safe way, but I do like to have the knowledge about what will and will not work in my mental file cabinet for when innovation is required.

Thanks again for all the help.

Not knowing what your "spider box" make it difficult to make suggestions.

1. If it is just a junction box with several standard 120V duplex receptacle (say 2 duplex receptacle or any multiple of 2) you could do the following. Use the green wire as a neutral (put white heat shrink on it). Run each hot into a GFCI receptacle along with a neutral. You can daisy chain several more receptacles off of each GFCI. The GFCI receptacle will come with a sticker that say something like "Ground not connected". Use the sticker.
   
2. If the ground and neutral are NOT bonded at the generator (no continuity between ground and neutral when the generator is off) you could attach the spider box to a copper rod driven into the ground and then connect neutral and ground inside the spider and to the ground rod.

6/4 is the correct way to go. If the 6/3 is in good condition and of reasonable length, you could probably sell it on eBay.

 

[theoldwizard1]

On the Hz not positive but I think I the only way to increase that would be to adjust engine rpm.??? Not positive.

Typically true.

With voltages reading a bit high and the frequency a bit low, are you certain you don't have a 50Hz model ?

 

[Rookie2]

1) If you loan the machine out then buy a 6' ground rod ,cut it in half and make two grounds and ground the machine ! I say that because not too many people can drive a 6' ground rod in.
I would ask the charity to hire an electrician and insure everything is safe at the site .
2) there could be an adjustable voltage regulator inside the cabinet, as you turn the rpm up to 60HZ you will need to turn the voltage down a bit.

 

[Desertfabworks]

Typically true.

With voltages reading a bit high and the frequency a bit low, are you certain you don't have a 50Hz model ?

Ya I'm positive its a 60Hz model. And it does have an internal voltage regulator. Next week I'm going to play with the rpm and adjust everything out. Get a new 6/4 100ft cord and move the spider box hubble connectors over to that. Take the 6/3 and put 120v twist locks on it and make it a 30A 12v cord. Get a couple ground rods and the the necessary ground leads and clamps. Make the tweaks and test everything out and ensure its all good.

Thanks again for all the help.

 

[theoldwizard1]

Is that thing 3 phase ?

 

[Desertfabworks]

Yes it does have three phase capabilities. I keep it in 1 phase operation. Here is the speck sheet: http://www.kwietpower.com/_docs/specs/DGK25B_Spec_B.pdf

 

[theoldwizard1]

I am not certain what this means exactly

Winding : 3-phase, 4-wire Star w/neutral/zig-zag

.

This is typically called 3 phase "Y"

If I had a generator that had such windings, I would make a "spider box" that would give me 3 -120V circuits.

What is missing from that picture is the ground wire. If you are grounding the gen set (recommended) then you need 5 wires to your spider.

 

[Desertfabworks]

Not sure but this generator is very popular. All the rental yards around here have 20 + of this model in their yards and they have been around for years. Its got to be a normal and excepted set up.

The generator has 2 50 amp hubbell twist locks which are for your runs to spider boxes. They are hot, hot, neutral, ground. and two edison 120 v duplex plugs which are gfi. hot neutral ground.

The generator has a grounding terminal lug on the frame but while it may be correct I have never seen a portable generator at a construction site, event or anywhere else where they have used a ground rod.

The main terminal connection for three phase has plugs for L1, L2, L3, N, ground. They are the large individual plug terminal connections.

The spider box I have is a JP Nolan 52301: http://www.jpnolan.com/NewJPNolanSite/PortablePowerCenters-CityofLAApproved.htm

It has a 50 amp twist lock in and a 50 amp twist lock out. Hot, Hot, Neutral, ground. It has 6 twist locks on it 5 120 v 20 amp one 30 amp 250 volt. Inside the box the incoming ground lead goes to the spider box metal body.

This spider box is a very popular name brand box and is UL approved so I think everything is fine with it and the generator. I think it all came down to the cord that I ordered was not wired correct and should have been a 6/4 instead of a 6/3

 

[CNGsaves]

That's going to be a nice Genset when you get it all figured out.

I presume it's diesel as low RPM 1800 with the sound-deadening enclosure will make that a QUIET genset living up to it's Kwiet name !!

What all money will you have invested in the Genset counting the salvage cost and the replacement Isuzu engine??

 

[theoldwizard1]

The spider box I have is a JP Nolan 52301: http://www.jpnolan.com/NewJPNolanSite/PortablePowerCenters-CityofLAApproved.htm

It has a 50 amp twist lock in and a 50 amp twist lock out. Hot, Hot, Neutral, ground. It has 6 twist locks on it 5 120 v 20 amp one 30 amp 250 volt. Inside the box the incoming ground lead goes to the spider box metal body.

Hubbell sells one with the exact same box (painted yellow) setup for 3 phase in. It has GFCI and is ridiculously priced !

 

[theoldwizard1]

That's going to be a nice Genset when you get it all figured out.

I presume it's diesel as low RPM 1800 with the sound-deadening enclosure will make that a QUIET genset living up to it's Kwiet name !!

Most travelling carnival have their own power source. Usually a 40' trailer with a couple of huge CAT stationary diesel engined 3 phase generators. Bigger than an I6 (V12 ?)

Even though they are in a trailer, they are very loud outside.

There junction boxes are made out of wood with big brass buss bars on the bottom. They use some kind of "pin" to connect the cable to the bus bar. Most of these are never locked, some watch out for little Johnny who like to open things up !

 

[ishiboo]

Most travelling carnival have their own power source. Usually a 40' trailer with a couple of huge CAT stationary diesel engined 3 phase generators. Bigger than an I6 (V12 ?)

Even though they are in a trailer, they are very loud outside.

There junction boxes are made out of wood with big brass buss bars on the bottom. They use some kind of "pin" to connect the cable to the bus bar. Most of these are never locked, some watch out for little Johnny who like to open things up !

Sounds like one or two hacks you've seen... I am guessing most bus bars these days would be properly constructed. Larger generators have single pole connectors, that could be what you are referring to.

 

[Desertfabworks]

Here is a pic of the generator. I got the bottom portion of the trailer done with a rhino liner type paint.

I need to paint the top portion but have not picked a color yet.

All together I think I have about $2000 invested in this including my spider box and cords. Having the ability to do all the work myself saved a lot of money.

I found the replacement engine at a military surplus auction in the crate brand new. Just had to tear out the old one and install the new one.

It had 400 hours on it when the engine blew. I put about 40 hours on it this weekend at the event. So it has about 460 hours on it now. 60 with the new engine.

It is very quite. You can have a conversation while standing next to it. Despite my protest they put this thing 3 feet from a guys 5th wheel and it ran all night and he said he never heard it.

Good little piece of equipment. Eventually I want to get and wire in a transfer switch system for my home so that I could plug the house in if I ever needed. But I think I will bite the bullet and hire someone when I get to that point.

 

[theoldwizard1]

I still say you need to look into a 3 phase spider box.

 

[Desertfabworks]

I still say you need to look into a 3 phase spider box.

A three phase spider box is pretty expensive and I do not have anything that runs on three phase nor do any of the local clubs that would want to borrow the trailer. I keep it locked in the single phase operation mode.

What would the advantage of having a three phase spider box give me?

 

[theoldwizard1]

A three phase spider box is pretty expensive and I do not have anything that runs on three phase nor do any of the local clubs that would want to borrow the trailer. I keep it locked in the single phase operation mode.

What would the advantage of having a three phase spider box give me?

Look at the picture I posted. You get 3 separate 120V circuits ! You are only getting 2 with your spider. You also are capable of more power out.

From DGK25B Spec Sheet

 

[theoldwizard1]

Did you ever figure out your low frequency issue ?

 

[Desertfabworks]

I will look into the 3 phase spider I see your point.

I have not had a chance to mess with the frequency issue had to move it to the back burner, Hope to get to tear into it in the morning.

 

[theoldwizard1]

I will look into the 3 phase spider I see your point.

It MIGHT be possible to rewire your current spider box to handle 3 phase depending on what kind of junctions/splices they use on the inside.

Of course, then you will need a 5 conductor cord !

 

[Desertfabworks]

Here are some pictures of the gen and spider box. I got two 4 foot ground stakes and made a mount so that I could store them on the trailer. I installed a ground connection on the spider box and got some 6 gauge stranded green wire to use for my ground leads.

Looking in the spider box my ground comes in and goes to the ground lug then out on the 50 amp plug. My individual outlets are not hooked to ground. This is the way it was designed from the factory but I'm wondering if it would be a good idea to tie each plug into the ground lug on the box?

I played with the engine on the generator and adjusted the rpm and got it set perfect at 60 Hz. And that allowed my voltage regulation to work properly once I was at 60 Hz so my out puts are perfect at this point and match the quality of my homes electricity.

I likely will not run the generator in 3 phase and will just keep it in the single phase for now. I'm searching for a good deal on some 6/4 cord but I took the 6/3 cord and put some 125v twistlocks on it and its now a 75 foot heavy duty 20amp cord.

Good progress just need to paint the gen now and make it look nice.

 

[theoldwizard1]

I likely will not run the generator in 3 phase and will just keep it in the single phase for now.

If you run across a good deal on another one of those boxes, it is very possible to wire it for 3 phase. Change the input connector to match what is on the generator (L21-50 or L21-60). Change the junction block to one that has 4 connections. Careful rewiring of all of 120 receptacles is all that is required. Remember you can not get a true 240V out of 3 phase, only 208V.