| Author |
Message |
Mr.ED (64.12.116.135)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 25, 2004 - 8:54 pm: | |
My onan generator is currently wired for 120 volt.It has no wiring diagram with it.The windings are wired 2/4 to one leg and 1/3 to the other.Anyone know how they should be wired for 240 volt.I want a 120 leg to each side of my panel box in order to run both cruise air if needed.They are currently wired one to each leg in the box so I can operate them both when plugged into 50 amp shore power.The generator and shore power go through an auto switch relay.The generator is and old one model 6.5nh-cr/12014d. |
Tom Caffrey (Pvcces) (65.74.66.104)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 12:16 am: | |
Shut off all power and disconnect all leads. Connect 2 to 3. This junction will become your neutral. 1 and 4 will each be 120 volts from the neutral. There will be 240 volts between 1 and 4.
At least, this is how I remember it. Easy, isn't it? Be sure to test the output carefully to make sure it turns out the way that you meant.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
bruce king (67.170.101.3)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 3:56 am: | |
if you wire these generators incorrectly, you can burn out the generator portion of the device. Suggest you call and get a manual on the beastie -- can't hurt, and usually costs around $15. To get the right manual you'll need the information off the serial number plate on the unit.
I bought one of these on ebay that someone had attempted to do this wiring on. The engine worked fine -- but the generator had been fried. I ended up resllilng it at a loss. |
Jim Ashworth (Jimnh) (172.136.128.100)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 8:41 am: | |
If your genset is connected to both poles of the panel at 120v, it should run both airs. If it is hooked to only one side of the panel, you can connect the two hot poles in the xfer switch ON THE GENSET INPUT SIDE together and when the xfer switch connects the genset, both sides of the panel will have 120v. This is exactly what happens when you plug your 50 amp cord into a 30 amp receptacle with a 50/30 adapter. The adapter connects both hot prongs of the 50amp plug to the one 120v input.
If this isn't perfectly clear, don't do anything until you get clarification. 6.5KW can get things mighty hot mighty fast.
Jim |
John that newguy (199.232.240.158)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 9:27 am: | |
Ditto to Jim's comment.
Unless you have a 220 volt appliance you need powered, don't
bother changing the genset's configuration. Our 30 amp Winnebago
wiring and 6.5k 110v genset powered both airs while cruising
(or stopped), while the shore power would power only one at a time.
Likewise, the 50am Georgie-boy 110v 6.5 genset powered both
roof airs at the same time (so did 50amp shore power).
If you don't need 220, I wouldn't change it and complicate matters. |
Doug Tuttle (66.82.9.22)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 10:26 am: | |
I have an 6.5 Onan genset. Here is what the installation manual says:
"Voltage selection on reconnectible single-phase generators is for use as 120/240 volts, 3 wire; or 120 volt, 2 wire. Use the connection for two wire service when used for motor starting such as air conditioning. Balance the load when conecting for three wire service."
I purchased my manuals from www.funroads.com.
HTH
Dug
75 MC8 |
Craig Smith (Craigs) (65.202.123.254)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 12:15 pm: | |
Hi Mr Ed,
I have a 6.5 Onan and the manuals. I had to connect the 4 wires to get my desired 120VAC. When I get home tonight, I'll look it up for you. I can't remember the numbers but it was something like Tom mentioned above.
Criag S |
DrivingMissLazy (66.168.175.51)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 26, 2004 - 1:47 pm: | |
The industry standard for single phase genset connections are:
120 volts two wire output:
connect leads 1 and 3 for L1.
Connect leads 2 and 4 for L2.
Either L1 or L2 can be utilized as the neutral and connected to ground.
120/240 volt three wire output:
Connect leads 2 and 3. This will be the neutral/ground connection.
Lead 1 will be the L-1 hot lead.
Lead 2 will be the L-2 hot lead.
Between L1 and L2 you will have 240 volts.
Between L1 and neutral and between L2 and neutral you will have 120 volts.
My personal recommendation is that you should never use the 120/240 volt configuration unless you actually have 240 volt appliances you need to operate.
Richard |
Jim-Bob (12.46.52.74)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 27, 2004 - 10:36 am: | |
Richard is right, especially about not using 120/240 on small gensets unless 240 is needed.
If you have two 120 volt circuits, you will need to manage the connected load for balance on each "leg". Many voltage regulators read one leg or the other and this can cause uneven voltage & overheating/overloading of one leg or the other. For instance, if the genset is rated for 50 amps total, that means each leg (winding) is rated for 25 amps. If you have 30-35 on one leg & 15 on the other you are cooking the insulation in the heavily loaded winding (leg) even though the genset is not overloaded.
But if you connect the genset for 120 only, you are connecting the windings in parallel so they automatically share any load evenly. Since genset manufacturers design the set so that overloading will stall the engine before damaging the gen end, you don't have to worry so much.
If you set the bus up with 120/240 main panel & 50 amp shore cord, but only 120 volt appliances, you can use any normal campground power you find.
The transfer switch would be hooked up 120/240 on the shore side and 120 only on the genset side. But you MUST use some sort of device to ensure that the genset system & the shore system can never be connected to the bus panel at the same time. This can be done with automatic or manual switches or even with cords & 50 amp receptacles. (Unplug the bus panel from the shore receptacle & plug it into the genset receptacle when you leave the campground.) My preference is a manual switch or interlocked breakers as is normal in marine applications. Simplicity = reliability.
My $.02 worth. |
Sam Sperbeck (204.73.103.254)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 27, 2004 - 3:03 pm: | |
Hi DrivingMissLazy,
In your above post I beleive there is an error in your instructions for wiring for 120/240 volt three wire output. You say to use leads 2 and 3 connected together for neutral/ground, and lead 1 for one hot (L-1) and lead 2 for the other hot (L-2). Shouldn't that have read to use lead 4 for the second hot (L-2)? Thanks for any clarification, Sam Sperbeck |
DrivingMissLazy (66.168.175.51)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 27, 2004 - 4:13 pm: | |
Sam, You are absolutely 100% correct. Thanks very much for catching this and bringing it to everybodys attention.
BTY, these leads from the alternator are typically marked G1 thru G4. Additionally, there are two small leads, typically marked F-1 and F-2 coming from the alternator. These are the field leads that come from the exciter field and connect to the output of the electronic voltage regulator. These are NEMA standards and generally hold true for most alternator manufacturers.
Richard
Richard |
Craig Smith (Craigs) (67.35.116.171)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 28, 2004 - 7:40 am: | |
Hi Mr Ed,
Well I had full intentions of looking this up after work but completely forgot about it. Here's the info from the Onan manual...For 120VAC M1 & M3 ungrounded black load, M2 & M4 grounded white load. For 220VAC M1 ungrounded black load, M2 & M3 grounded white load, M4 ungrounded black load.
HTH, Craig S |