This is a generic question. I have a portable generator that bogs down when a large load is placed on it. I have checked the governor movement and linkage all is fine. Any suggestions generator puts out correct voltage it is a 5500 watt genetic.
Is the 5500 watts surge or nominal?
How much of a large load by wattage?
Is the large load 120v or 240v?
Do you have a tachometer and if so how much is the rpm drop under load? and what is the no load rpm?
How much of a large load by wattage?
Is the large load 120v or 240v?
Do you have a tachometer and if so how much is the rpm drop under load? and what is the no load rpm?
No sir no surging of engine. The large load is a window air conditioner, which it used to run with no problem. But this is a 3500 watt load. The engine is steady at 3200 rpm, when I place this air conditioner the genset seems to make no effort to increase rpm. I can manually increase throttle and it works. I am hoping it isn't a internal governor fault.
Surge in my question doesn't mean the engine is surging. Generators have two ratings. One is for a continuous load like say a toaster. And the surge wattage is for like starting a motor or compressor. Surge load is always higher than running load. So a generator may have a 5500 watt rating which could be the surge rating but is only rated to run 5000 watts continous I am assuming that 3500 watts is a 240 air conditioner correct.
Is that 3200 rpm no load or with the load. If that is no load there should be an adjustment screw or something similar to put more tension on the governor spring to increase engine rpm. No load should be 3700-3750 roughly.
Is that 3200 rpm no load or with the load. If that is no load there should be an adjustment screw or something similar to put more tension on the governor spring to increase engine rpm. No load should be 3700-3750 roughly.
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Here is another question is the AC a 60HZ or is it a 50hz unit? Currently 3200 rpm is output 53.3hz and if you are in a 60hz area the rpm as IL said need to be 3750 rpm off load which should droop to 3600 rpm under load for a 2 pole alternator.
Just can't assume everyone is operating in an area that uses 60hz as there are places that is using 50hz systems.
Just can't assume everyone is operating in an area that uses 60hz as there are places that is using 50hz systems.
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Can you provide a picture and the ID plate information of this generator.
As a general rule, most American portable generators are governed at max 3600 RPM (loaded) to provide approximately 60Hz. Very few have a low idle unless it has controller solenoid operation.
Canada and Europe run their electric power grid and generators at 50Hz the last time I checked.
This unit could simply have some partially plugged carburetor jets not letting enough fuel through under high load demand. That is common with generators when they sit too much, or the fuel stabilizer starts breaking down.
As a general rule, most American portable generators are governed at max 3600 RPM (loaded) to provide approximately 60Hz. Very few have a low idle unless it has controller solenoid operation.
Canada and Europe run their electric power grid and generators at 50Hz the last time I checked.
This unit could simply have some partially plugged carburetor jets not letting enough fuel through under high load demand. That is common with generators when they sit too much, or the fuel stabilizer starts breaking down.
Douglas Lee
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yup, 3600 plus rpm for a 60 Hz load.
Doug Lee
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Doug Lee
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The Wattage rating numbers on generators can be confusing because many buyers/users do not understand "surge rating" as compared to constant load rating.
Consumers usually buy underpowered portable generators and are disappointed when it will not operate everything in their house or shop. Advertising of the generator products are questionable at best.
Manufacturers (especially the cheap ones) often boast their surge Wattage rating numbers in bold print while minimizing the steady Wattage rating. Wattage numbers are manipulated because the general public does not understand that Wattage is the work produced by the generator. The more work you want out of a generator, the higher the Wattage rating must be.
There are generator Wattage calculators online for reference of minimal generator requirements.
To clarify, surge ratings are meant to calculate sudden temporary loads such as a refrigerator/freezer compressor starting. Or a A/C compressor start up. Once these components startup they run on steady Wattage.
Sorry a 5500-Watt generator was not designed to run a whole house. They will get a person through a cold snap or summer power outage using a few lights, a refrigerator or microwave and a couple of small space heaters. They are not meant for running main A/C heat pump units. Even a window A/C unit puts a strain on them to a point that the generator can/will stall, or the window unit will fail due to repeated lack of startup Wattage. Under supplying the startup Wattage is a slow death for any electrical motor.
In reality, a "whole house" house generator rating starts out at the minimum range of 12,000 Watts (12KW).
Consumers usually buy underpowered portable generators and are disappointed when it will not operate everything in their house or shop. Advertising of the generator products are questionable at best.
Manufacturers (especially the cheap ones) often boast their surge Wattage rating numbers in bold print while minimizing the steady Wattage rating. Wattage numbers are manipulated because the general public does not understand that Wattage is the work produced by the generator. The more work you want out of a generator, the higher the Wattage rating must be.
There are generator Wattage calculators online for reference of minimal generator requirements.
To clarify, surge ratings are meant to calculate sudden temporary loads such as a refrigerator/freezer compressor starting. Or a A/C compressor start up. Once these components startup they run on steady Wattage.
Sorry a 5500-Watt generator was not designed to run a whole house. They will get a person through a cold snap or summer power outage using a few lights, a refrigerator or microwave and a couple of small space heaters. They are not meant for running main A/C heat pump units. Even a window A/C unit puts a strain on them to a point that the generator can/will stall, or the window unit will fail due to repeated lack of startup Wattage. Under supplying the startup Wattage is a slow death for any electrical motor.
In reality, a "whole house" house generator rating starts out at the minimum range of 12,000 Watts (12KW).