Im having trouble finding schematics/wiring diagrams for my 1989 Mobile traveler (Chevy P30/454ci). The trouble is that when my generator is on, the AC items are reading at 135-160V and the DC items are reading at 21-24V. I cannot run anything with the generator on for fear of burning things up (I discovered the issue when I turned the generator on and my DC bulbs immediately blew.) Any suggestions as to what the problem is, or where I might find a schematic for my coach?
1989 mobile traveler questions
- Thread starter luster
- Start date
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Carl L
Moderator Emeritus
I would check the output voltages of your generator, it sounds as if the regulator is defective.
RLSharp
Well-known member
luster said:
The voltage output is controlled by a voltage regulator but the speed at which the engine is turning also effects the voltage output. When voltage regulators fails, it is much more common to get no voltage; high voltage due to a failed regulator is very uncommon. You need to find someone to check the speed of you genset. My guess is that your frequency is also high because the engine is running too fast.
Carl L
Moderator Emeritus
Whatever it is, the voltage regulation on the generator is malfunctioning. Get the genset repaired.
RLSharp
Well-known member
Carl L said:
Carl, If the genset speed is grossly high, the voltage regulator can't properly regulate the voltage. That is why I suggested that luster either check it's speed or have it checked. A frequency meter will give a good indication if the engine is running too fast. The regulator can only do so much and I have never heard of one that "regulated" the voltage to such a high level, if the genset is turning the proper RPMs.
Gary RV_Wizard
Site Team
Your generator is over-revving, which raises its output voltage and frequency. That in turn mucks up the converter and 12v power. You need a new speed regulator on the genset.
RLSharp
Well-known member
RV Roamer said:
It could be that the governor needs to be adjusted. Just for kicks a few years ago I intentionally increased the speed on my genset just to see how high the voltage would go. As I remember, I had the voltage up to about 130-135 volts and I think the frequency was somewhere around 74-75 Hz. That was with no load on the genset. A faulty or maladjusted governor can cause the genset RPMs to be high, as can an improperly adjusted carburetor. The voltage regulator can only give "good" voltage regulation if the RPM of the genset (as controlled by the governor) is close to where it should be. Unless one has the instruments to measure either frequency or engine RPMs and voltage under load, they should seek professional help. There simply is no way to properly do it by ear or just measuring the voltage.
BTW, the most common cause of voltage regulators failure is shutting the genset down with a heavy load on it.
Gary RV_Wizard
Site Team
Voltage regulation in this type of generator consists of making the RPMs exactly right, typically something like 3600.
RLSharp
Well-known member
RV Roamer said:
Gary,
Does a genset of this age typically have a voltage regulator that controls the governor or is that a mechanical linkage? On mine (built in 1992) the voltage regulator electronically controls the governor, but the genset has to be operating within certain specs in order for the regulator to be able to manage the governor. BTW, my genset is a Kohler.
Lou Schneider
Site Team
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- Mar 14, 2005
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In 1989, everyone was using mechanical governors.
The easiest way to check the frequency of the generator is to get a Kill-A-Watt meter. They're available for about $30 at hardware stores, etc. and are handy for a whole lot of stuff, including monitoring the voltage when you're plugged into shore power.
Just plug the Kill-A-Watt into an extension cord. The voltage and frequency functions will work. You only have to plug something into the front of the Kill-A-Watt when you want to measure how much current or power (watts and watt-hours) is being used.
The easiest way to check the frequency of the generator is to get a Kill-A-Watt meter. They're available for about $30 at hardware stores, etc. and are handy for a whole lot of stuff, including monitoring the voltage when you're plugged into shore power.
Just plug the Kill-A-Watt into an extension cord. The voltage and frequency functions will work. You only have to plug something into the front of the Kill-A-Watt when you want to measure how much current or power (watts and watt-hours) is being used.
RLSharp
Well-known member
Lou Schneider said:
Thanks Lou, that's what I suspected.
Gary RV_Wizard
Site Team
In a direct AC power generation type of generator, voltage, frequency and RPM are intrinsically linked, you can monitor any of the three and use it to control the RPMs. As Lou says, they used to be all mechanical, but now they are probably more sophisticated. The trick is to monitor the loading and get the RPMs back up to the standard value (1825, 3650, or whatever it is designed for) as quick as possible before any damage is done.
Inverter type generators are different - they don't run at constant RPMs and the inverter does the voltage regulation. There is still a load feedback system that increases engine RPMs as needed to deliver more DC power to the inverter.
Inverter type generators are different - they don't run at constant RPMs and the inverter does the voltage regulation. There is still a load feedback system that increases engine RPMs as needed to deliver more DC power to the inverter.
