User Guide

Application guidelines
24 AB237986441643en-US0701
The lockout may be cancelled by resetting the
power mains (disconnect L-N) for approximately
5 sec.
Compressor models SY240 to SY380 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:
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
unbalance is 2%. Voltage unbalance causes high
amperage over one or several phases, which in
turn leads to overheating and possible motor
damage. Voltage unbalance is given by the
formula:
Vavg = Mean voltage of phases 1, 2, 3.
V1-2 = Voltage between phases 1 & 2.
V1-3 = Voltage between phases 1 & 3.
V2-3 = Voltage between phases 2 & 3.
| Vavg - V1-2 | + | Vavg - V1-3 | + | Vavg - V2-3 |
2 x Vavg
% voltage
unbalance
=
x 100
Voltage unbalance
Compressor
start
Phase monitoring
0 1 s 6 s
Phase sequence module logic
In case of phase reverse error:
Appro. 760 ms
Appr. 1second
In case of phase loss error:
120ms 120ms 120ms 400ms
500ms 500ms
Electrical data, connections and wiring