motor winding connection, p-leads

[brackman47]

I've encountered a motor that has p-leads that I've never seen before. It has the standard 9 leads that most dual voltage 3 phase motors have,(t1-t9) as well as 3 P-leads (p4,p5,p6). The nameplate is quite clear on the connection: parallel t4-p4,t5-p5,t6-p6 for your standard low voltage (208-230) connection and cap the leads for your standard 460 volt connection. The motor is obviously Y connected. Any ideas on what these leads are for? The motor nameplate states that it is thermally protected. Could this mean that p4 is tied to t5, p5-t6 and p6-t4? I haven't ohmed the motor yet but will have an opportunity soon. I just don't understand how the thermal protection would work for the high voltage Y connection scheme.

 

[Ranch]

What is the make and model? I may have an idea.

 

[mdshunk]

P1 P2 and P3 sound like Klixon terminals with the heating element.

 

[brackman47]

it is a Marathon motor on a prefabbed COOK fan unit for an HVAC system. The P-leads are 4,5 & 6, not 1,2 & 3. The motor model is a 56TI7G531E1P. I haven't had any luck on Marathon's website either. I'm not so worried about getting the motor to run, the connections are clearly spelled out on the nameplate. I have some testing/QC documentation to complete and I want to megger the motor correctly. Plus, I'm just curious.

 

[tkb]

I looked on the Marathon web site and could not match the number of the motor.
Most likely it is custom to the manufacturer of the fan.

Their FAQ lists an email address for help with this.


Q. What if my model number does not appear when I type it in the Product AC or DC Motor search?

A. The model you have requested may not be a current stock catalog model, please contact motor.help@marathonelectric.com for assistance.