21
AB243586442172en-001401
Electrical data, connections and wiring
Compressor models SH090-105-120-140-161-184,
incorporate an internal reverse vent valve which
will react when the compressor is run in reverse
and will allow refrigerant to circulate through
a by-pass from the suction to the discharge.
Although reverse rotation is not destructive for
these models, it should be corrected as soon
as possible. Repeated reverse rotation longer
than 24hours may have negative impact on
the bearings. Reverse rotation will be obvious
to the user as soon as power is turned on: the
compressor will not build up 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 motor protection.
The lockout may be cancelled by resetting the
power mains (disconnect L-N) for approximately
5 seconds.
Compressor models SH180, 240 to 485 are
delivered with an electronic module which
provides protection against phase reversal and
phase loss at start-up. Apply the recommended
wiring diagrams from section “Suggested wiring
diagram logic”. 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
second after compressor start-up (power on
L1-L2-L3).
Vavg = Mean voltage of phases 1, 2, 3.
V1-2 = Voltage between phases 1 and 2.
V1-3 = Voltage between phases 1 and 3.
V2-3 = Voltage between phases 2 and 3.
| Vavg - V1-2 | + | Vavg - V1-3 | + | Vavg - V2-3 |
2 x Vavg
% voltage
imbalance =
x 100
The operating voltage limits are shown in the
table section “Motor voltage”. The voltage applied
to the motor terminals must lie within these
table limits during both start-up and normal
operations. The maximum allowable voltage
imbalance is 2%. Voltage imbalance causes high
amperage over one or several phases, which in
turn leads to overheating and possible motor
damage. Voltage imbalance is given by the
formula:
Voltage imbalance
Compressor
start
Phase monitoring
0 1 s 6 s
Phase sequence module logic
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:
In case of phase loss error:
Appro. 760 ms
120 ms120 ms120 ms
400ms
Appr. 1second
500ms
500ms
Application Guidelines
Summary of Contents for SH485
Page 2: ......