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Norskeman's avatar
Norskeman
Explorer
Jul 03, 2014

Yanaha generator volatage low - low load

Was at the races and my generator would put out 117 volts when carrying 8-12 amps load but at low load, 3-4 amps, the voltage was only 105 volts.

The voltage readings are from my surge protector - which shuts off power to the RV when voltage is less than 106 volts. So if I want to power up the RV I have to turn the surge protector off. Just don't like running items at such a low voltage. I installed the surge protector last year and this is the first time I noticed this problem. May have always been there but I never bothered to check the voltage output of the generator.

It is a 4000 watt Yamaha generator. Model YG4000D. Looks similar to this one - mine does not have a volt meter - just a green power light.

  • lawrosa's avatar
    lawrosa
    Explorer
    Jul 03, 2014
    Probably the voltage regulator..Since its brushless it should have two capacitors and two diodes in the head unit... You need to check these..
  • Learjet's avatar
    Learjet
    Explorer
    Jul 03, 2014
    ...or problems with your surge protector reading the generator voltage. I would try a true RMS AC voltage meter to verify there is a problem with the generator.
  • M_GO_BLUE1's avatar
    M_GO_BLUE1
    Explorer
    Jul 03, 2014
    Norskeman wrote:
    Was at the races and my generator would put out 117 volts when carrying 8-12 amps load but at low load, 3-4 amps, the voltage was only 105 volts.

    The voltage readings are from my surge protector - which shuts off power to the RV when voltage is less than 106 volts. So if I want to power up the RV I have to turn the surge protector off. Just don't like running items at such a low voltage. I installed the surge protector last year and this is the first time I noticed this problem. May have always been there but I never bothered to check the voltage output of the generator.

    It is a 4000 watt Yamaha generator. Model YG4000D. Looks similar to this one - mine does not have a volt meter - just a green power light.



    ...and therein lies your first mistake
  • Jaxom's avatar
    Jaxom
    Explorer
    Jul 03, 2014
    I have a garage-kept Yami 2400. 2010 model year. It has about 10-15 hours on it. I was having problems like those described. I took it in and the repair shop found out that some connections were corroded. They cleaned everything up and put dielectric grease on the connectors and all is good. You might wish to check yours.
    Good Luck. Keep us informed.
  • Bobbo's avatar
    Bobbo
    Explorer II
    Jul 05, 2014
    M GO BLUE wrote:
    Norskeman wrote:
    Was at the races and my generator would put out 117 volts when carrying 8-12 amps load but at low load, 3-4 amps, the voltage was only 105 volts.

    The voltage readings are from my surge protector - which shuts off power to the RV when voltage is less than 106 volts. So if I want to power up the RV I have to turn the surge protector off. Just don't like running items at such a low voltage. I installed the surge protector last year and this is the first time I noticed this problem. May have always been there but I never bothered to check the voltage output of the generator.

    It is a 4000 watt Yamaha generator. Model YG4000D. Looks similar to this one - mine does not have a volt meter - just a green power light.



    ...and therein lies your first mistake

    Absolutely correct. It astounds me how many folks pay big bucks to get an EMS to protect their rig from bad power, then when they get bad power, disable the EMS.

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