Detecting relay state on a Kohler auto transfer switch

[ckindel]

I want to detect generator status via digital inputs on my home control system.

I have a Kohler generator with a Kohler G120 automatic transfer switch.

I _COULD_ wire a relay into the 220V in the transfer switch to detect when the house is on generator power.

HOWEVER, it really looks like my transfer switch has contact points for just this purpose. The problem is I can't find any real documentation and I don't want to screw something up.

The transfer switch control board has the following terminals which are documented in the manual have thusly:

ER - Emergency Relay
ERD - Emergency Relay Disconnect
NR - Normal Relay
NRD - Normal Relay Disconnet
GND - Ground
+12V - +12V

At first I thought, COOL, ER & NR close with ground when ever either relay is active. But after actually testing these I found while on normal power there is +12V across ER/GRD, ERD/GRD and V/NC across NR/GRD and NRD/GRD. I have not tested while the generator is actually working because that's a PITA in my house to test.

So now I'm not sure what these terminals actually are. I was hoping someone here might actually KNOW. If these terminals are for external CONTROL of the relays I'd have thought I'd see +12V or something across NR or NRD while in normal operation.

Anyone actually know for sure?

 

[BraveSirRobbin]

A link to a manual would go a long way here

 

[BLH]

I am not 100% sure this is what you need.
http://www.genxnow.com/ebay/kohler-ats-parts-manual.pdf

 

[BraveSirRobbin]

Browsing that manual it seems there is an extensive set of LED's to determine switch status. Do you happen to have a W800 or receiver that would receive DS10a's by any chance? I think I would consider using CdS photocells over the LED's. I have an easy schematic that can be used to do this (with a DS10a) but it could be modified to work with your controller system. What monitoring hardware do you have?

 

[mikejrc]

After reading the manual a little bit, it seems like this relay status terminal strip is basically used to assist you in testing/troubleshooting the relays involved in the operation of your unit.

but also they could have been designed to allow an external alarm/remote monitoring module made by kohler.

I was unable to find anything on their website about your unit, it could be an older model that they no longer sell. The new units kohler make have the capability of alarm or remote monitoring so chances are yours had that capability.

I would contact your kohler service people in your area and they should be able to tell you.

but you could study the sections in the manual that deal with testing those relays and their status and follow the control logic and come up with your own solution.
the manual shows the close/open status of those relays during normal and emergency conditions etc.

i personally wouldnt mess with it unless your are following the procedure stated in the manual for testing only and wait until you verify if those terminal are indeed designed for remote or alarm status, hope this helps....

 

[signal15]

After reading the manual a little bit, it seems like this relay status terminal strip is basically used to assist you in testing/troubleshooting the relays involved in the operation of your unit.

but also they could have been designed to allow an external alarm/remote monitoring module made by kohler.

I was unable to find anything on their website about your unit, it could be an older model that they no longer sell. The new units kohler make have the capability of alarm or remote monitoring so chances are yours had that capability.

I would contact your kohler service people in your area and they should be able to tell you.

but you could study the sections in the manual that deal with testing those relays and their status and follow the control logic and come up with your own solution.
the manual shows the close/open status of those relays during normal and emergency conditions etc.

i personally wouldnt mess with it unless your are following the procedure stated in the manual for testing only and wait until you verify if those terminal are indeed designed for remote or alarm status, hope this helps....

Here are a bunch of links to various manuals on the unit:
http://www.google.com/search?q=filetype%3Apdf+kohler+g120&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a

Sorry, didn't have time to look through them all.

 

[gatchel]

Get out the meter and start checking...voltage , continuity, etc...

 

[ckindel]

Browsing that manual it seems there is an extensive set of LED's to determine switch status. Do you happen to have a W800 or receiver that would receive DS10a's by any chance? I think I would consider using CdS photocells over the LED's. I have an easy schematic that can be used to do this (with a DS10a) but it could be modified to work with your controller system. What monitoring hardware do you have?

Thanks for all links & thoughts folks! Really appreciate it.

I spent some time testing with my multi-meter and while NR/NRD and ER/ERD go to +12V when Emergency & Normal power are active (respectively...yes they seem backwards) running them across a relay causes the OPPOSITE LED to get some juice. I suspect these terminals are not to be used unless JP6/JP5 (resistors) are cut (just as JP2 needs to be cut to enable the test switch). This leads me to believe these are for CONTROL of the unit...and I aint about to cut resistor on this board without really knowing the truth.

So... BraveSirRobbin has presented me with what seems like a really neat option. I don't have a DS10a, but it seems there should be photocells that go over LEDs that I can tie into my digital inputs. Who can give me pointers to quality photocell options that go over LEDs?

-cek

 

[mikejrc]

Thanks for all links & thoughts folks! Really appreciate it.

I spent some time testing with my multi-meter and while NR/NRD and ER/ERD go to +12V when Emergency & Normal power are active (respectively...yes they seem backwards) running them across a relay causes the OPPOSITE LED to get some juice. I suspect these terminals are not to be used unless JP6/JP5 (resistors) are cut (just as JP2 needs to be cut to enable the test switch). This leads me to believe these are for CONTROL of the unit...and I aint about to cut resistor on this board without really knowing the truth.

So... BraveSirRobbin has presented me with what seems like a really neat option. I don't have a DS10a, but it seems there should be photocells that go over LEDs that I can tie into my digital inputs. Who can give me pointers to quality photocell options that go over LEDs?

-cek

Hello Charlie
I still think you should contact kohler or a factory service shop and ask about these terminals, reading the service manual that someone linked today seems to confirm that they are designed for service/troubleshooting your unit rather than being used for remote controlling or monitoring.
I'm not saying they couldn't be used for it but it doesnt hurt to ask

 

[BraveSirRobbin]

.
So... BraveSirRobbin has presented me with what seems like a really neat option. I don't have a DS10a, but it seems there should be photocells that go over LEDs that I can tie into my digital inputs. Who can give me pointers to quality photocell options that go over LEDs?

I'll be doing a How-To on this (once I get my CES reviews out first )

 

[ckindel]

I'll be doing a How-To on this (once I get my CES reviews out first )

Just letting everyone know that I figured it out with the help of someone on electronics.stackexchange.com.

All I needed was a simple circuit that took the 12V down to 5V via two resistors. See here:

http://electronics.stackexchange.com/questions/9008/need-circuit-to-close-switch-on-detecting-current-12v/9009#9009

I built two of them; one each for normal power and one for emergency power. I now have two digital inputs connected up to Premise.