Need replacement for obsolete relay.

[mkgrady]

A customer has a heat relay that is stuck in the on position so it must be changed. It is a Minivector model 50240. It has an internal 24 volt control transformer with built-in power and control wire leads. It is connected at the electric panel through a knockout except for the thermostat wire connection.

I look at the power wire leads and find wires connected to two 240 volt heat circuits and find the contacts are meant for two heat circuits. I did not bother to sort out how the circuitry functions thinking I would just buy a direct replacement and hook it up the same way as the old one.

There are two problems. I am unable to find a replacement relay and I can't figure out what the contacts do in the relay. I find the connection diagram unhelpful. Does any body know of a direct replacement for this relay? Except for the self contained control relay which I can provide seperately, is this a simple DPST relay? I do have a picture of the connection diagram but I don't know how to post it.

 

[jumper]

I do have a picture of the connection diagram but I don't know how to post it.

Here is one method for posting a picture.

http://forums.mikeholt.com/showthread.php?t=83435&page=2&p=760873#post760873

PM me if you need further help.

 

[mkgrady]

Here is one method for posting a picture.

http://forums.mikeholt.com/showthread.php?t=83435&page=2&p=760873#post760873

PM me if you need further help.

Thanks for the link. I will have ro find my photobucket account. It has been years and only used it once. I will post the picture after I figure it all out

 

[GUNNING]

Stop, reevaluate, proceed.

Stop, reevaluate, proceed.

Sounds like a replace not repair item. If you can't find the manufacturer then I would stop, and start over; by reinstalling the heat strips with new product. That way it would be up to code and you would have the right size crts to the devices.

 

[mkgrady]

Sounds like a replace not repair item. If you can't find the manufacturer then I would stop, and start over; by reinstalling the heat strips with new product. That way it would be up to code and you would have the right size crts to the devices.

There is nothing wrong with the heaters. The problem is with the relay that turns them on. My plan is to find a replacement relay with a 24 volt coil. My problem is I cant understand the connection diagram and I can't just ring it out because it is stuck closed. I think if I post the connection diagram I will get helpful feedback but I have yet to figure out how to post a picture of it.

I suspect it is simply a DPST relay and I know the contacts are rated 25 amps. I guess I need to research how to upload the pic to photobucket. I have the photobucket account but no luck getting the picture uploaded to it.

 

[kwired]

There is nothing wrong with the heaters. The problem is with the relay that turns them on. My plan is to find a replacement relay with a 24 volt coil. My problem is I cant understand the connection diagram and I can't just ring it out because it is stuck closed. I think if I post the connection diagram I will get helpful feedback but I have yet to figure out how to post a picture of it.

I suspect it is simply a DPST relay and I know the contacts are rated 25 amps. I guess I need to research how to upload the pic to photobucket. I have the photobucket account but no luck getting the picture uploaded to it.

Is this just a simple relay with incorporated control transformer to control a remotely located heater?

If so, I would think there are other brand replacements that would work just fine.

If this is a timed delay relay like is often installed in air handlers with electric heat, just about any other brand of relay usually works, fitting it in the same position as original is sometimes a problem. They main thing to remember is to make sure blower is always on whenever any heat is running, and that high limits are not bypassed - they are the last line of protection should the blower fail.

 

[mkgrady]

Is this just a simple relay with incorporated control transformer to control a remotely located heater?

If so, I would think there are other brand replacements that would work just fine.

If this is a timed delay relay like is often installed in air handlers with electric heat, just about any other brand of relay usually works, fitting it in the same position as original is sometimes a problem. They main thing to remember is to make sure blower is always on whenever any heat is running, and that high limits are not bypassed - they are the last line of protection should the blower fail.

Yes it is a simple relay with a control transformer but the connection diagram is clear as mud to me. If I knew it was just a double pole single throw relay I would just hook it up exactly the same without having to trace out the heater circuits. The heaters are radiant with no moving parts.

 

[kwired]

Yes it is a simple relay with a control transformer but the connection diagram is clear as mud to me. If I knew it was just a double pole single throw relay I would just hook it up exactly the same without having to trace out the heater circuits. The heaters are radiant with no moving parts.

If you have two control leads and four power leads it is a little hard to go wrong as long as you don't intermix control and power. If you have more control leads it gets more complicated, but about all you could possibly have extra is the "C" lead of the control voltage if you would have a control powered electronic thermostat.