ecm to pcs conversion bryant 574B036


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Old 01-03-23, 07:26 AM
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ecm to pcs conversion bryant 574B036

ecm 2.3 gone bad. unit is 14 years old. it is a natural gas packaged unit. Looking for a basic wiring diagram to convert ecm to psc
 

Last edited by hmalvarez82; 01-03-23 at 07:27 AM. Reason: misspelling
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Old 01-07-23, 07:07 AM
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It looks like you have the easy select board with Aux terminals that are normally for the EAC control but can be used to energize the coil of a fan relay.






 

Last edited by Houston204; 01-07-23 at 02:12 PM.
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Old 01-04-23, 01:09 PM
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The easiest way to do it is to use the thermostat G wire and C to activate the relay.
Connect the blower motor common to 120v common.
Connect the desired speed wire thru the relay.
On a G demand the blower will operate.

There is an ICM board that takes the commands and generates 24v outputs to the ECM.
You will have to check those 12 wires/pins to find which ones supply the 24v signal you need.
Downloadable manual
 

Last edited by PJmax; 01-04-23 at 01:44 PM.
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Old 01-07-23, 07:04 AM
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If that motor pin readings are anything like the FV4 it will only use a DC signal for G.




 
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Old 01-07-23, 07:25 AM
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Like this...


 
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Old 01-07-23, 07:32 AM
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This is the rest of the wiring diagram for that unit...


 
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Old 01-07-23, 09:48 AM
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It may be necessary to configure the thermostat for electric heat so it energizes the fan control "G" on demand for heat.
 
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Old 01-03-23, 09:20 PM
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Welcome to the forums.

There really isn't a basic wiring diagram. This is something custom as you are installing a different type motor that requires multiple relays to allow the furnace to control the blower. A quick easy way to get back in service is get your blower motor and a 24vac DPDT relay. Set the blower up for one speed now and work on building a multispeed system. You can post the wiring diagram from your furnace. Post the model number too.

How to insert pictures.
 
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Old 01-04-23, 07:20 AM
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thank you for the reply Pjmax

ive got the psc motor with as close specs as possible
it has the appropriate capacitor in the box. i also have the
DPDT relay. the model number of the Bryant unit is
574BNW036090NB. i’ll find a wiring diagram online because the
diagram on the panel is old and faded. Gosh there must be hundreds of wires
all over. those guys on you tube just yank off most of them out and start from scratch.
Again , thank you for your help
 
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Old 01-09-23, 01:21 PM
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thank you houston204 for all of this valuable
information. there is a gas/electric switch on the
thermostat. it’s on gas now. just need to get back up
on the roof and get the connections done when this
rain lets up.
 
 

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