Wiring Onan genny for 120/240 50 amp service

[PwrWgnWalt]

( from my 'Refurbish' blog on our Beach-Craft, edited )

Generator: Onan 5.0 BGA-3CR/16004A   (5000 watts, or 5.0 kW)
   (3=voltage code for 120/240 single phase; C=Reconnectable; R=Remote Start; Spec "A")
    120 volt:  41.6 amp
    120/240 volt:  20.8 amp each leg

Re-doing existing 30 amp service in MH to now be 50 amp service, using 6/4 cable (6 gauge, 4 conductor wiring, cost $3.78/ft at my local Graybar distributor). Generator is currently wired for "120 volt, 2 wire" service (M1 & M3 joined, and M2 & M4 joined inside genny junction box, behind start switch and fuse panel.  Of note, all of my M wires are white, and are imprinted with the M#).

So, here's the plan...  (please, anyone, let me know if I got something wrong!)

Will be 'reconnecting' so there is "120/240 volt, 3 wire output"; only M2 & M3 will be connected inside the junction box:
M1 will attach to the black 6 gauge wire of the 6/4 cable,
M2/M3 will connect to the white 6 ga. wire,
M4 will connect to the red 6 ga. wire, and
the green ground wire will attach to the genny case, as it is now.

From there, the 6/4 cable will run to the new 50 amp receptacle.  The shore power line plugs into this receptacle to power the MH from the genny.


The shore line cable runs through the Progressive Industries EMS-HW50C, then into the new WFCO-8950 distribution panel:
The Black wire (M1) will feed the left-side 50 amp main breaker,
the White wire (M2/M3) will connect to the Neutral buss,
the Red wire (M4) will connect to the right-side 50 amp main breaker, and
the Green wire (ground) will connect to the Ground buss (connecting only to the vehicle frame, not to Neutral circuit).

The rest of the circuit breaker ("cb") and house wiring is std from there on... just have to decide which side to put each circuit.  Front A/C will go on side with power when using 30 amp adapter plug on shore power cable, rear A/C will go on other side (that would not get power when using a 30 amp adapter on my 50 amp shore power cord).


Thanks!
-Walt

[DaveVA78Chieftain]

The BGA generator wiring you stated is per the manual so that should be OK

Question: Are you setting this up for generator mode only?  Your description implies you are connecting the generator directly to the Distribution panel but then talks about shore cable.  It is a little confusing.

You said:

WFCO-8950 distribution panel

Did you mean the WFCO-8930/50 Distribution panel that uses an external converter?



Asking because:
WFCO-8930/50 "Distribution panel" (AC/DC without converter) can be used with either 30 or 50 amp service.

WFCO-8900 Series "Power Centers" (AC, DC, plus converter) are only rated for 30 amp service.

WFCO-9900 Series "Power Centers" (AC, DC, plus converter) are rated for 50 amp service.

Dave

[PwrWgnWalt]

Thanks Dave!  I somehow skipped right over that 'small' part of the system!  i??
I've edited the post to be correct. 

I was little confused by the manual's use of 'white' & 'black' wires for M1-M4, but after working out the wiring diagram I 'got' that it was only to show neutral and hot.

Yes, it is the WFCO 8930/50 Distribution Panel (which, curiously, is only labeled 8950) which uses a separate, stand-alone converter. I am using the Boondocker PM4B-75.

I'll post pictures of the redo...

[DaveVA78Chieftain]

You welcome

The M1-M4 wiring
There are 2 seperate stator windings in the genny.  They are either wired in phase (120VAC double amps like 12VDC batteries in parallel) or 180 degrees out of phase (240VAC that has = amperage on each leg).

Dave

[PwrWgnWalt]

Question about generator circuit breakers:

Inside the Onan genny junction box, the original power lead (black) wire went thru a circuit breaker ("cb")... It is of the old pop-out circular button/aviation style and is not specifically marked, but I did find a label loose inside the box and believe it came from the cb.  This label reads:

1648-006-040    125/250 VAC   4077

I believe this may be the original Onan part (a 40 amp cb, Onan # 320-0734) or a 40 amp replacement, given the -040 number.  Original 120 VAC svc was rated at 41.6 amps.

My questions are...
Now that I have 2 legs of 120/240 VAC svc, rated at 20.8 amps each, I'm postulating that I need to replace that existing cb with two 20 (or 25?) amp cb's (one for each power leg, M1 & M4)... Like this:
http://www.ebay.com/itm/Siemens-W58-XC4C12A-20-20a-250VAC-push-button-breaker-/111309316991?pt=BI_Circuit_Breakers_Transformers&hash=item19ea8d637f
Anyone see a fault with this thinking, or have a genny with other arrangements?

What kind/style of cb's does your genny use? 

Thanks everyone,
-Walt

[ClydesdaleKevin]

So in theory, you could wire in another box and outlet, and by using a couple of switches to make it live when you needed it, you could have a 240 volt outlet to run a REAL welder?

Hmmmmmm...

Kev

[DaveVA78Chieftain]

Those should work however here is the original Onan 20 amp CB (320-0692)
http://www.ebay.com/itm/ONAN-RV-GENERATOR-CIRCUIT-BREAKER-320-0692-/320307453231

[DaveVA78Chieftain]

So in theory, you could wire in another box and outlet, and by using a couple of switches to make it live when you needed it, you could have a 240 volt outlet to run a REAL welder?

If done correctly on a model that does have 240 capability, yes Kevin.  Walts 5.0 BGA does.

[PwrWgnWalt]

Great thought, Kev!   First, I'd have to get a welder...      I'll be real good this year, and maybe Santa will bring me one?  In truth, I did consider a 240 VAC option, but I don't have anything that could use it, presently.

Thanks for the part # Dave... I couldn't find a listing in my parts book or any other manuals that specified what cb's to use for the 120/240 option.

I ended up ordering two of those 20 amp Siemens W58-XC4C12A-20 circuit breakers, since they have the screw-type connections and were only $7.50 each, postage paid ($15 total).  I think they'll work fine, just was a little concerned that at 20 amps, they might be too low for the genny output (and draw of the two A/C units)... oh well, time will tell.

Didn't get it all done this weekend, but got the cabinet area re-done (which was also part of the remodel of the mattress area), the Distribution Panel mounted, the generator re-wired, and the new power line run into the panel and hooked up to the 50 amp main breakers. The rest is easy enough, just have to find the time!
W%


Thanks again guys!
- Walt

[DaveVA78Chieftain]

Well Shucks Walt your welcome, P/N came from the 4.0/5.0 BGA parts book (available for free to CW members in the members area) 

Normal AC breaker size in an RV is only 20 amps.  Your biggest concern is if other items draw enough to create a problem when the AC on the same leg starts up.

Dave

[PwrWgnWalt]

Received the new Seimens 20 Amp pop-out, or push in, circuit breakers this week and installed them today. Here are a few pictures of the finished project to rewire ("reconnect") the Onan for 120 / 240 VAC service.

The black wire at the bottom breaker is the M1 lead (L1), and the red wire at the top breaker is the M4 lead (L2).

I did have to open up the little holes in the cover for the cb heads to stick through; the new ones are 15/32", the original one was 7/16".  A right angle drill extension from Harbor Freight, and their step drill bit, made it easy!

[DaveVA78Chieftain]

Love it a plan comes together! - Dave

[PwrWgnWalt]

After 1.5 months goofing around with the 12volt wiring, a new Power Distribution Center, installing an EMS, installing the Boondocker 75 Amp 4-stage converter/charger,  conversion to 50 Amp service, and remodel of the bed area, got the Onan fired up to test the new re-wiring!


Who-hoo!  It worked well!   Little readout of the EMS shows L-1 and L-2 to produce even voltages (depending on load, between 114 vAC and 123 vAC), and it shows the Amperage draw of each line, too. 


So far, it works as intended...

[DaveVA78Chieftain]

Great.  Now you be a  cookin!

Dave

[FastGlassman69]

So in theory, you could wire in another box and outlet, and by using a couple of switches to make it live when you needed it, you could have a 240 volt outlet to run a REAL welder?

Hmmmmmm...

Kev

Yes Kevin, that made my imagination go hmmmmmm too, I'd love to have my machine on board! Bobby