480 Volt RPC Using Modified Steveco 90-66 Potential Relay

Attached is a complete schematic diagram for a 480 volt RPC which uses a modified Steveco 90-66 potential relay.

The transforming action of the idler motor itself is used to control the P.R. and transformer-like lines are drawn on the motor's schematic to emphasize its transforming action and the appropriate points to connect the P.R.'s "sensitive" coil.

The P.R.'s contactor is in its customary connection.

All capacitors are shown as are all bleeding/voltage-stabilizing resistors.

The Steveco 90-66 has a number of terminals which are spares and which have no internal connection.

Disassembling a 90-66 is relatively easy: remove the bracket (requires a #2 Phillips driver) then separate the housing (requires a T8 Torx driver).

The coil terminal is connected to (2) using a Fast-On connector which may be easily removed.

Solder this Fast-On to the selected spare terminal.

Assemble in reverse order of disassembly.

Peter

Thanks for the diagram. I am sure it will come in useful for many people.

I assume it comes from this users thread:
http://www.practicalmachinist.com/vb/showthread.php?t=166126

"I assume it comes from this users thread"

Correct.

It was buried in the earlier thread, and was revised by way of explanation several times.

The diagram and explanation, above, incorporates all related revisions.

Will this only work with 9 wire motors?

Peter,

A couple of brief questions. Will this only work with 9 wire motors or will this work with 3 wire? My 460 Reliance/Baldor 15hp is a standard 3 wire, 460VAC single voltage electric motor. It is marked as a 4 pole, 3 hots and a neutral-I'm guessing.

Here are 2 links-one with the specs to a similar motor and the other is the info packet for the similar motor, and a picture of my spec plate. And........ Yes, I know the prices of these things are ridiculous, but I bought mine for less than $300 at a surplus industrial supply. It was never installed or used, and still strapped to the original pallet.


Anything you can offer to push me along would be greatly appreciated.

Thanks in advance,

Matt


http://attachments.temcoindustrialpower.com/Data_sheet/Baldor-ZDPM18015C-BV.pdf

Products: AC Motors: ZDBRPM18154C: Baldor Electric Company, a leader in energy efficient electric motors, linear motors and adjustable speed drives industry