1949 relay 1

[daddy1]

i have an old relay that i need help whith.
it is 2" widex3"long x1.5"high has 2 poles on each end and 2 in the middle. on the in side has 2 coils and 8 diodes.
all solid black sealed, used to switch 2 water pump motors when one got hot. need replacement no numbers or manufactor info.

thanks
we

 

[jsummerfield]

I would start from scratch with the purpose and functions provided by the old relay with the assumption that I cannot find the exact replacement without numbers on the relay or other documentation. Determine why there are two coils. Is one to activate one set of contacts for one motor, return to a center off and the other coil to activate a different set of contacts for the other motor?

Determine whether the voltage that energizes each of the coils and AC or DC.

Determine the voltage and current required for the load or loads.

You might advise the equipment associated - including manufacturer and model. However, finding a pdf file on the web for something quite old is unlikely.

You mention that the relay is used to switch two water pump motors. As I understand your post, one motor overheated. Is this a problem with the motor? What size? I assume that the motor must be a small fractional hp if activated with a small relay.

The diodes suggest DC coils or DC loads.

What more can you tell us?

John

 

[daddy1]

thanks john
i dont have any other info other than it was used in a johnston-pruitt air handler. they are no longer around.
was hoping someone would know about this unit and come up whith a diagram w/a part number that would lead to the companey that made the relay. thanks for your quick responce

thanks
we

 

[jraef]

Some pump mfgrs make special relays like that which act to protect the motors or increase system reliability by alternating the pumps etc. It would be unwise to guess at the funtion if you have no documnetaion. They could be overload relays, thermal relays, timing relays, liquid sensing relays etc. etc. etc. There are countless possibilities. If the pumps have a separate mfgr information from the air handler, you might try there. If not, you are shooting in the dark.

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