View Full Version : three terminal start relay

16-06-2013, 03:13 AM
Ok, my brain is melting on this one.

I swapped a compressor (aea3425yxa, 1/5hp) for a new compressor. Same techumseh model number, but they were out. However, they did some searching and I got the same compressor, rebadged under a manitowok part number. New compressor still shows aea3425yxa.

Difference is in the start relay. The new start relay has two terminals for the compressor (m and s) and only one other terminal. I'm used to four terminal relays, m, s, and a place to put line voltage and another to attach the start capacitor.

The tech sheet from tecumseh specifies that it should be used with a start capacitor. I'm very hesitant to hook up the old start relay because the compressor is a burnout and I haven't excluded the start relay.

So, any hints on how to hook up a start relay with only one terminal (aside from the compressor hook-up) ? Is this a wrong part, meant for some compressor that doesn't require a start capacitor?

I have been reading schematics in my refrigeration bible, and haven't found a thing.

Old relay on left new one on right.

Any pointers would be greatly appreciated.


install monkey
16-06-2013, 08:26 AM
its a LST comp-low starting torque
no capacitor needed on that compressor- its a rsir comp just live to the relay and neutral to the overload.

best check with the manufacturer of the unit to see if a med/high start torque compressor is needed

16-06-2013, 12:03 PM

The tecumseh esp guidebook lists it as requiring a capacitor.

Thank you.

Do these guys often change the specifications on a compressor and reuse the model number?

install monkey
16-06-2013, 12:46 PM
info on dataplates on compressors

16-06-2013, 01:26 PM
Interestingly enough, their nomenclature doesn't specify low starting torque anywhere in that pdf. It only shows normal and high starting torque.

install monkey
16-06-2013, 01:34 PM
AE170AL-726-J7 AEA3425AXA 115-60-1 R-12 1/5 2600 Normal * P82627‡ P83458 1/4 S 5/16 S LP3
didnt copy too well- it states the part numbers for the relay and klixon overload and refers to it as normal starting:)

16-06-2013, 03:25 PM
"Normal starting" is "low start torque" i.e. no capacitor?

16-06-2013, 03:29 PM
Also, perhaps I'm reading this wrong... this is from Tecumseh's android app.


install monkey
16-06-2013, 04:06 PM
looks like ur ringing technical to clarify
some compressors can have caps fitted as an option but the relay would need 2 connections to bridge it