PDA

View Full Version : Replacing fan motor relay switch with upgraded switch


DaleTex
Nov 25, 2008, 12:15 PM
Hello,
I've searched online to locate a replacement fan motor relay switch for an old Fedders propane heating unit in my greenhouse. The replacement should be fairly easy to do, however the part I was needing ( RBM 84-20103-301A) was listed as obsolete and was replaced by (McQuay part # 061019403). The parts are the same 24 V 50/60 Hz but the contacts (5) are numbered differently and the layout of the contacts are similar and I could hook them in a similar fashion as the old part but I am not wanting to blow out a $31 part. Do I hook them up in a "one for one" sequence as the old part or by the contact numbers? If anyone can help here is a photo of the parts side by side. I sure would appreciate any clue.
DaleTex

hvac1000
Nov 25, 2008, 02:29 PM
Hello,
I've searched online to locate a replacement fan motor relay switch for an old Fedders propane heating unit in my greenhouse. The replacement should be fairly easy to do, however the part I was needing ( RBM 84-20103-301A) was listed as obsolete and was replaced by (McQuay part # 061019403). The parts are the same 24 V 50/60 Hz but the contacts (5) are numbered differently and the layout of the contacts are similar and I could hook them in a similar fashion as the old part but I am not wanting to blow out a $31 part. Do I hook them up in a "one for one" sequence as the old part or by the contact numbers? If anyone can help here is a photo of the parts side by side. I sure would appreciate any clue.
DaleTex


Your search for 84-20103-301 returned the following item(s): Description of Model Number Searched:Relays and Transformers Suggested Replacement:90-293Q Description of Suggested Replacement:Fan Relay, Type 84, 24 VAC Coil, SPDT. Coil Data: 90 Ohms DC Resistance, 125 mA (Nominal), 3 VA (Nominal), 4 VA (Inrush)
Descriptive Comments or For Whom Made:White-Rodgers Relay

Take me to information on: 90-293Q (http://www.white-rodgers.com/wrdhom/common/ptech/relays/info_list_relays.htm#90-293Q)

Here is link to wiring diagrams. These relays have been made by many different companys but they are all the same except the part numbers. This wiring diagram will help you decide where to land the wires.



http://www.white-rodgers.com/wrdhom/pdfs/06_Cat_pages/Cat_06_pg0114.pdf

letmetellu
Nov 25, 2008, 04:06 PM
If you did not get any information about this relay when you bought it you can always take apart the old relay and see which post are the coil and which post are the normaly open and which poles are the normaly closed.
You can then check the new relay with an ohm meter and find the same info about the new relay. Then connect the wires the way they need to be operate your fan motor.

MarkwithaK
Nov 25, 2008, 05:33 PM
Most of these relays will have a brief schematic on the side to show you the terminals for the coil and the terminals for you switched leg.

Sargoo
Sep 18, 2012, 11:27 AM
I know this post is long over, but I wanted to add some thoughts for future readers.


As far as I can tell, the correct part would be a White-Rogers (ex.) 90-370 24VAC coil SPDT relay (which looks exactly like the new one in the above picture)

Garden variety, available online, or at an electro distro store.

Mark is correct, every relay I've ever seen has a little schematic on the side, you can see which pins are coil, etc... there's no need to start bashing it with a hammer to see what kind of tinkly parts are inside.