Generator install/////ATS

[TobyD]

Recently there has been an increase of home backup power/ generator supply in our area.Most often these are being installed as a entire or whole house supply.Commonly 20 kw with a service rated disc or equivalent.

With that being understood ,Now ,We are required to test run and set up the run time weekly or etc..Our inspection dept. does verify the voltage output.We are having issues with a small amount of voltage being present with the Xfer being in the open position during the generator run cycle back feeding onto the incoming supply. We have had as much as 10 v. and as low as 1.5v.

Our concern is ,with all the ( as an example residents gen sets) in a neighborhood having similar voltage back feed multiplied is the linemans safety .Thank you..

 

[GoldDigger]

If you are measuring with a high impedance voltmeter, you are most likely seeing capacitively coupled "phantom" voltage, which will not supply more than a milliamp or two. It is not a hazard.

 

[iwire]

Now ,We are required to test run and set up the run time weekly or etc..

There is no requirement for weekly testing of optional standby systems.

Our inspection dept. does verify the voltage output.We are having issues with a small amount of voltage being present with the Xfer being in the open position during the generator run cycle back feeding onto the incoming supply.

With a properly wired transfer switch it is impossible to back feed into the the incoming supply..

I agree with Golddigger it is simply a meter issue / phantom voltage.

Check this out from NEMA and if needed print it out to give to the inspector.

https://www.nema.org/Technical/Documents/Bull_88_reaffirmed_12_15_11.pdf

 

[TobyD]

Thank you, That is the answer I needed .I too am in agreement with your statement.As so far as mandatory run time procedure and set up we aren't required to do anything with the exception of making sure the supply in operable when we complete the install.Thanks again..

 

[TobyD]

Here is the reason for concern.The neighbor in question has several homes , most all have a direct back up generator supply.I have only heard and have not witnessed that a few weeks ago there was a main power outage.During the outage naturally the gen. backup began to run...From what I understand the city street lights(only on this particular street) were receiving enough stray voltage for the lights to come on.All these transfer switches are of one companies supply.

 

[ActionDave]

Recently there has been an increase of home backup power/ generator supply in our area.....

....We are having issues with a small amount of voltage being present with the Xfer being in the open position during the generator run cycle back feeding onto the incoming supply. We have had as much as 10 v. and as low as 1.5v.

Our concern is ,with all the ( as an example residents gen sets) in a neighborhood having similar voltage back feed multiplied is the linemans safety .Thank you..

Here is the reason for concern.The neighbor in question has several homes , most all have a direct back up generator supply.I have only heard and have not witnessed that a few weeks ago there was a main power outage.During the outage naturally the gen. backup began to run...From what I understand the city street lights(only on this particular street) were receiving enough stray voltage for the lights to come on.All these transfer switches are of one companies supply.

Somethings not adding up. Where is the illegal generator hook up, or where is the power that lit the street lights coming from?

 

[iwire]

Here is the reason for concern.The neighbor in question has several homes , most all have a direct back up generator supply.I have only heard and have not witnessed that a few weeks ago there was a main power outage.During the outage naturally the gen. backup began to run...From what I understand the city street lights(only on this particular street) were receiving enough stray voltage for the lights to come on.All these transfer switches are of one companies supply.

The source of this power cannot be comming from any properly installed generator / transfer switch.

As Dave mentions there may be an incorrectly wired generator back feeding or it could be as simple as the lights where on a different transformer.

 

[Dennis Alwon]

As others have said if the generator is properly wired and there is some phantom voltage present, then that is not the cause as phantom voltage will not be capable energizing equipment.