Tecumseh AH5540E Service Handbook page 30

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SERVICE HANDBOOK
Relay Type
Current Relay RSIR and CSIR
PTC Relay RSIR and PSC
Potential Relay CSR
Potential Type Relay Supplier Code Designations
In recent years, Tecumseh has used an increasing number of potential relays with hermetic
compressors. A large number of these have been used on air conditioning applications,
but there are also many other applications. Since there are many variations with regard to
these relays such as number of terminals, coil group, hot pick up, and mounting position,
an explanation of the code numbers should be useful in the field.
Tecumseh has two major suppliers of potential relays: the General Electric Company and
the White Rodgers Company. An explanation of the code designation for relays manufac-
tured by each of these companies is provided in Figures 3-14 and 3-15.
NOTE: The G.E. and White Rodgers relay model numbers indicate the position the relay
is to be mounted. Refer to Figures 3-14, 3-15 and 3-16. It is of utmost importance that the
relays be mounted in the required position. Mounting in any other position can change the
relay's operating characteristics enough so that the compressor will not start properly. This
can result in compressor motor failure.
Table 3-4: Facts about Starting Relays
Compressor Motor
Type
• Sense starting current to main (run)
• Contacts normally open
• Contacts close and then release in less
• Must be installed vertically since con-
• Sense starting current to start winding
• Solid state device whose resistance in-
• Takes 3 to 10 minutes to cool down be-
• Sense voltage generated by start wind-
• Contacts normally closed
• Contacts open in less than 1 second as
Characteristics
windings
than 1 second as motor starts
tacts open by gravity
creases with heat from current as motor
starts
tween operating cycles
ing
motor starts