PTC
FU
FU
C1
EC
TH
N
L1
L2
L3
C1
MS
IOL
Comp.
13
ELECTRICAL CONNECTIONS AND WIRING
Three phase motor
protection and
suggested wiring
diagram
Three phase compressors are inter-
nally protected by a temperature /
current-sensing bimetallic protector,
connected to the neutral point of the
star-connected stator windings. This
internal overload line break protects
the motor against overheating, cur-
rent overload and locked rotor con-
ditions. If the motor were to be over-
loaded and the protector trips, all
3-phases are cut out. It might take up
to several hours to reset and restart
the compressor.
FU
Fuses
MS
Main switch
C1
Compressor contactor
TH
Thermostat
EC
External controls
COMP
Compressor
PTC
Crankcase heater
IOL
Internal overload line break
Three phase electrical
characteristics
Compressor
model
LRA
(Locked Rotor Amp)
A
MCC
(Maximum Continuous Current)
A
Winding resistance
(between /- 7% at 25°C)
Ohm
3
4
9
3
4
9
3
4
9
NTZ048
32
16
22
10.1
4.8
5
2.80
11.55
13.10
NTZ068
48.5
25
29
14.8
8.4
8.5
1.58
7.11
9.70
NTZ096
72
32
20.4
10.1
1.20
5.03
NTZ108
72
45
57
21.4
12.1
11
1.20
4.00
2.54
NTZ136
97.2
51
64
29
14.3
15
0.98
3.80
2.54
NTZ215
147.7
74
110
42.3
22.3
23
0.57
2.23
1.26
NTZ271
198
96
150
56.5
27.0
30
0.41
1.61 0.84
