Electrical data, connections and wiring
If any thermistor exceeds its response
temperature, its resistance increases above
the trip level (4,500 Ω) and the output relay
then trips -ie. contacts M1-M2 (or 11-14 for SM/
SZ175-185) are open. After cooling to below
the response temperature (resistance < 2,750
Ω), a 5 minute time delay is activated. After this
delay has elapsed, the relay is once again pulled
in ie. contacts M1-M2 (11-14 for SM/SZ175-185)
are closed. The time delay may be cancelled by
means of resetting the mains (L-N disconnect) for
approximately 5 sec.
A red/green twin LED is visible on the module.
A solid green LED denotes a fault free condition.
A blinking red LED indicates an identifiable fault
condition:
Phase sequence and reverse
rotation protection
Use a phase meter to establish the phase
orders and connect line phases L1, L2 and L3
to terminals T1, T2 and T3, respectively. The
compressor will only operate properly in a single
direction, and the motor is wound so that if the
connections are correct, the rotation will also be
correct.
Compressor model SM112-124-147
have no
internal reverse rotation protection. If reverse
rotation occurs it will be obvious as soon as
power is turned on. The compressor will not
build-up any pressure, the sound level will be
abnormally high and power consumption will be
minimal. In such case, shut down the compressor
immediately and connect the phases to their
proper terminals. Prolonged reverse rotation will
damage the compressor.
A phase sequence detector is strongly
recommended.
Compressor models SM / SZ 084 to 185
(except
SM112-124 & 147) incorporate an internal reverse
vent valve which will react in the presence of
reverse rotation and will allow refrigerant to
circulate through a by-pass from the suction to
the discharge. Although reverse rotation is not
destructive, even over long periods of time up
to several days it should be corrected as soon
as possible. Reverse rotation will be obvious
to the user as soon as power is turned on; the
compressor will not build up any pressure, the
sound level will be abnormally high and power
consumption will be minimal. If reverse rotation
symptoms occur, shut the compressor down and
connect the phases to their proper terminals. If
reverse rotation is not halted, the compressor
will cycle off on the internal motor protection.
Compressor models SY / SZ 240 to 380
are
delivered with an electronic module which
provides protection against phase reversal and
loss at start-up. Apply the recommended wiring
diagrams. The circuit should be thoroughly
checked in order to determine the cause of the
phase problem before re-energizing the control
circuit.
The phase sequencing and phase loss
monitoring functions are active during a 5 sec.
window 1 sec. after compressor start-up (power
on L1-L2-L3).
Should one of these parameters be incorrect, the
relay would lock out (contact M1-M2 open). The
red led on the module will show the following
blink code:
In case of phase
reverse error:
Appro. 1 second
In case of phase
loss error:
Appro. 1 second
PTC overheat
Appr. 1 second
Delay timer active (after PTC overheat)
Appr. 1 second
Application guidelines
22
FRCC.PC.003.A5.22
