Tecumseh AEA4440YXA Service Data Book page 28

relay coil energized and the relay starting contacts
open. When power is shut off to the motor, the volt-
age drops to zero, the coil is de-energized, and the
start contacts reset.
When changing a compressor relay, care should be
taken to install the replacement in the same position
as the original.
Relay Type
Current Relay
PTC Relay
Potential Relay
28
Chapter 3
Table 3-7: Facts About Starting Relays
Compressor
Motor Type
RSIR and CSIR
RSIR and PSC
CSR
Figure 3-19. Potential type relay.
Characteristics
•
Sense starting current to main (run) windings
•
Contacts normally open
•
Contacts close and then release in less than 1 second
as motor starts
•
Must be installed vertically since contacts open by
gravity
•
Sense starting current to start winding
•
Solid state device whose resistance increases with
heat from current as motor starts
•
Takes 3 to 10 minutes to cool down between operating
cycles
•
Sense voltage generated by start winding
•
Contacts normally closed
•
Contacts open in less than 1 second as motor starts