Rotation meter for transfer switch

[Cow]

I have a customer with two different sites that they'd like a manual transfer switch added too. Have any of you guys found a decent outdoor panel mount rotation meter or similar that would work well for a portable generator connection? Maybe something I could mount in a box nippled off the side of the transfer switch, etc?

This is for a 480/277v farm service to keep a well and some other things running for the cattle.

I googled and found one from Knopp and another from PC-S but would rather ask someone on here with some firsthand experience before I roll the dice with either of those.

Thanks for the help.

 

[Cow]

No takers, huh? These things must be pretty uncommon.

 

[Jraef]

So you are thinking of this as in putting a portable meter permanently attached to a panel, is that right? Because if so, part of the problem is that this is something that is not really done. Once you connect a permanent piece of equipment, a meter to show you the phase rotation is kind of pointless.

What you CAN easily get however is a phase monitoring RELAY, one that INCLUDES rotation detection. For those, you would set it up as, let's say, A-B-C rotation, then if someone connects the genset backward, the relay trips. All you have to do then is hook up a pilot light to let the guy making the connection know he screwed up, and interlock that relay with the entire control system so that they can't run anything until he fixes it. I've done that hundreds of times on pump station controllers, where for example the portable genset might be the one owned by the Sewer Dept., or the next time it might be one owned by the Fire Dept. in an emergency. Very common application that way. I've even done a couple with a large reversing contactor down stream of the main CB that just goes ahead an corrects the rotation so that nobody has to re-wire anything during a storm at night while the sewage is flowing around their feet... Kind of an expensive way to go though, a pilot light is cheaper.

The side benefit is that these relays typically also do over / under and unbalanced voltage protection.

Here's one with two sets of contacts; one to lock out the controls, one to turn on the idiot light. There are lots of others available out there.

 

[Cow]

That's a good idea Jraef, we use quite a few phase fail relays in pump panels. Adding one to a transfer switch with a pilot light would be a simple solution and should work well for what I'm proposing to the customer.

Thanks again!

 

[Jon456]

Shouldn't whomever is connecting the generator have a phase rotation meter to confirm correct rotation before connecting and energizing the panel?

I do think it's a good idea to affix a large weatherproof label to the transfer switch showing the correct phase rotation for the site.

 

[tom baker]

Seems like the generator should be set up so it can only connect one way. My standard is to have clockwise rotation for all locations

 

[Jon456]

Seems like the generator should be set up so it can only connect one way. My standard is to have clockwise rotation for all locations

Perhaps their plan is to only rent a generator as needed.

 

[Cow]

Perhaps their plan is to only rent a generator as needed.

Yep, they weren't interested in a permanent generator installation.