Voltage Regulars: Choose Your Vendor Carefully!

There certainly are reasons to think about voltage regulators, but as many of us understand, 99% of the generators sold don’t have them, and if voltage droop is acceptable from no load to full load, there may be little reason for your generator to have one, arguably so!

I recommend that you NOT buy Generators with VRs  from Vendors who do not stock parts, and have no interest in the business of selling power products other than making the initial sale. I know how easy it is to get all excited about the low, low price, but if it’s not the KISS design I talk about on pages like the ST pages, how are you going to fix it when it fails?  The following are very typical emails, and I thought I might share as a warning. I selected these because they are newer, but I receive quite a few of these!  If your generator has a VR, you better know the vendor and where you will source a spare when you need it, or how to adapt an after market unit.

Email addresses and names withheld/changed as a matter of privacy, of course.

—–Original Message—–
From: ******************
To: GeorgeB
Sent: Tue, 4 Dec 2007 7:10 am
Subject: Voltage Regulator

I purchased aChinese DG10 with 20HP engine and 8.5KW Power head about a year ago. The Voltage regulator is burnt. I am having trouble finding this part to purchase. I don’t know if it is the same KZT-12D or JF 1401 or other. Do you know where I can purchase this part?

-Up a Creek W/o a VR


Greetings Up a Creek,

There seem to be a lot of different designations out there, and I am unfamiliar with these units you mention. It is probably a good idea to go back to your vendor and see if he will source the part required. Sometimes a picture of the components inside the doghouse can tell me more about your particular unit, are you positive your unit has a voltage regulator?

I have devoted several pages on utterpower.com about voltage regulators and the fact that many of them are responsible for the failure of the unit.Your personal experience will add to our database, and I will appreciate any follow up email with what you eventually determine.

Sometimes a picture of the components inside the doghouse can tell me more about your particular unit, are you positive your unit has a voltage regulator??

George B.

—–Original Message—–
From: ******************
To: GeorgeB
Sent: Tue, 4 Dec 2007 8:56 am
Subject: Voltage Regulator Search


My name is Tom. These pix aren’t very good taken with my cell phone,  but I think you can get the picture. The # on the Regulator is GFC9-1. One company here in Las Vegas NV, wants to try a different regulator in the unit($400.00), but I would like to get the same one if possible. The unit was purchased on E-bay through a dealer in CA, which has disappeared if you know what I mean.



Hi Tom,

Getting  a lot of feedback from around the world about generator failures and what causes them is a great privilege, and as I tell folks, it is the power of ‘utterpower’.There are a lot of small Importers, and even some larger ones that buy a container load or two of these Chinese Gen sets, and never stock even one set of parts for them. The VR is often reported as the failure point.

If you can’t find your vendor, it may be a good idea to consider the better made VR, and your after market supplier will certainly need to know the field current stated on the generator head; (hope it’s there). You will want a VR that will have an upper limit for current, and will not fry the field during an anomaly.

$400 sounds like a lot, but totally in line with a lot of quotes I’ve had reported here. I have received word of quotes as high as $1000USD for parts an labor to replace a VR in a high end 6KW power plant.

Wishing you the best, but not much help here.


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