| Author |
Message |
Jim Schrecengost (Schrec)
Registered Member
Username: Schrec
Post Number: 48
Registered: 2-2007
Posted From: 24.2.127.94
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 21, 2007 - 12:41 pm: | |
Can someone please tell me where the relay connection on the generator goes to?? From what I've read it goes to the starter/generator relay and to activate the no gen light?? Is this correct? And if my coach does not have these two items what does it get connected to?? Any help would be appriciated.
Schrec |
Jerry Liebler (Jerry_liebler)
Registered Member
Username: Jerry_liebler
Post Number: 291
Registered: 3-2005
Posted From: 67.140.170.17
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 21, 2007 - 7:02 pm: | |
Jim,
Your bus has a 12 volt system and a 50DN gear driven alternator that the manuals call a 'generator'. The 'r' terminal goes to a 6 volt relay's coil. The closure of this relay only happens when the 'generator' is putting out 12 volts. The contacts of this relay are used to allow large loads, which would discharge the battery, to run while the engine is running. The large loads controlled by the 'r' terminal relay are usually such things as the HVAC blowers. This relay may also be used for a 'not charging' indicator light. Since the 'r' terminal produces pulses of 12 volts that are on about 1/2 the time it requires a 6 volt relay and also is an excellent source of a 'tachometer' signal. Exactly what uses the 'r' terminal relay had can be found in the wiring diagrams of your particular bus.
Regards
Jerry 4107 1120 |
Frank Allen (Frank66)
Registered Member
Username: Frank66
Post Number: 61
Registered: 10-2005
Posted From: 64.12.117.73
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 22, 2007 - 11:11 am: | |
Starter gen relay should be in the right rear elec panel, it is a double realy, when the bus is started and the alt starts to charge it disables the start circuit to prevent accidental trippin of the start circuit after the bus is already running.
Frank Allen |
Laryn Christley (Barn_owl)
Registered Member
Username: Barn_owl
Post Number: 84
Registered: 10-2006
Posted From: 153.2.247.30
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 24, 2007 - 9:54 pm: | |
The main job (not the only job) of the double relay in the starting circuit is to keep the generator from attempting to charge while you are cranking. The less drag on your starter the better. |
Tom Caffrey (Pvcces)
Registered Member
Username: Pvcces
Post Number: 1139
Registered: 5-2001
Posted From: 204.245.250.25
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 26, 2007 - 12:04 am: | |
Laryn, I don't think you would have much luck measuring the additional load of the turned on generator while cranking, even if you were set up to try it.
The RPM of the generator is too low to produce much additional load.
I call that relay a protection relay because both of it's functions are protective.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher
Ketchikan, Alaska |
Laryn Christley (Barn_owl)
Registered Member
Username: Barn_owl
Post Number: 86
Registered: 10-2006
Posted From: 153.2.247.30
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 26, 2007 - 12:18 am: | |
“The main job (not the only job) of the double relay in the starting circuit is to keep the generator from attempting to charge while you are cranking. The less drag on your starter the better.”
That’s what several of the “Old timer’s” have told me. I had to redo that circuit on my bus due to some butchered repairs that had been made in the past. Following the schematics, it made good sense to me.
“The RPM of the generator is too low to produce much additional load.”
I am lucky to have real world experience with this one. I was surprised to learn how much effort it took even at low rpms.
“I call that relay a protection relay because both of it's functions are protective.”
Can you go into more detail? I’m here to learn.
Thanks,
Laryn
(Message edited by barn_owl on October 26, 2007) |
Tom Caffrey (Pvcces)
Registered Member
Username: Pvcces
Post Number: 1140
Registered: 5-2001
Posted From: 204.245.228.208
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 28, 2007 - 12:02 am: | |
Laryn, the only two functions of that relay, AFAIK, are prevention of the starter engaging after the generator is charging and prevention of quickly discharging of the 8D batteries is the generator fails while on the road.
If the generator succeeded in charging while the engine was being cranked, the load would produce power that the batteries could use. The amount would be reduced by the inefficiencies of the starter and generator, but maybe upwards of 70% of the load would be recovered.
From that point of view, I don't think that the load would be significant even if the generator could put out some power while cranking.
That's the way I see it, anyway.
Tom Caffrey PD4106-2576
Suncatcher
Ketchikan, Alaska |