© Danfoss | Climate Solutions | 2022.03
Electrical data, connections and wiring
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.
Phase sequence and reverse
rotation protection
The lockout may be cancelled by resetting the
power mains (disconnect L-N) for approximately
5 seconds.
Compressor models MLM/MLZ116 -130-160-
200-240 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).
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:
Appr. 1 second
In case of phase loss error:
Appr. 1 second
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
19
AB243586442698en-000601
Application Guidelines
Single compressors
