Application guidelines
17
FRCC.PC.004.A9.22
Electrical connections and wiring
The trickle circuit provides the facility of heating
the compressor crankcase by feeding a small
current to the auxiliary winding and the run
capacitor (See the drawings page 14.)
By using PSC or CSR starting systems, compressor
models MT / MTZ 018 - 022 can be operated
without crankcase heaters as the heater function
is provided by the trickle circuit.
For the larger single phase compressor models
MT / MTZ 028 - 064, the use of the PTC crankcase
heater is recommended.
PSC wiring may be used for refrigerant circuits
with capillary tubes or expansion valves with
bleed ports. Pressure equalization must be
ensured before start-up because of the low
starting torque characteristics of this system.
CSR wiring provides additional motor torque
at start-up, by the use of a start capacitor in
combination with the run capacitor. This system
can be used for refrigerant circuits with capillary
tubes or expansion valves. The start capacitor is
only connected during the starting operation, a
potential relay is used to disconnect it after the
start sequence.
Some applications with high differential pressure
can require a very high starting torque. For such
cases the CSR starting kit can be converted to
a very high starting torque kit by an additional
start capacitor of 100 μF parallel to the start
capacitor of the CSR kit. This configuration
can also be used to reduce erratic starting at
unfavorable conditions such as very low ambient
temperature or weak voltage.
Nominal capacitor values
and relays
Trickle circuit
PSC wiring
CSR wiring
Single phase electrical
characteristics
* PSC: Permanent Split Capacitor
CSR: Capacitor Start Run
(1) Run capacitors: 440 volts
(2) Start capacitors: 330 Volts
LRA - Locked Rotor
Current (A)
MCC - Maximum
Continuous Current (A)
Winding resistance (Ω)
( ± 7 % at 68° F)
Motor Code
1
5
1
5
1
5
Winding
run
start
run
start
MT/MTZ018
51
40
13
10
1.32
4.16
1.32
3.75
MT/MTZ022
49.3
41
17
15
1.18
2.26
1.32
3.75
MT/MTZ028
81
51
25
20
0.67
1.80
1.05
3.19
MT/MTZ032
84
70
26.5
20
0.62
2.84
0.78
4.14
MT/MTZ036
84
60
30
22
0.62
2.84
0.78
4.14
MT/MTZ040
99
-
34
-
0.53
1.83
-
-
MT/MTZ044
97
-
31
-
0.45
1.90
-
-
MT/MTZ050
114
-
36
-
0.37
1.79
-
-
MT/MTZ056
136
-
42.5
-
0.32
1.61
-
-
MT/MTZ064
143
-
46
-
0.32
2.10
-
-
Models
PSC/CSR*
CSR only
Run capacitors (1)
Start capacitors (2)
Start relay
(A) µF
(C) µF
(B) µF
50 Hz
MT/MTZ018 JA-5
20
10
100
3ARR3J4A4
/RVA6AMKL
MT/MTZ022 JC-5
20
10
100
MT/MTZ028 JE-5
20
10
100
MT/MTZ032 JF-5
25
10
135
MT/MTZ036 JG-5
25
10
135
60 Hz
MT/MTZ018 JA-1
15
10
100
3ARR3J4A4
/RVA6AMKL
MT/MTZ022 JC-1
30
15
100
MT/MTZ028 JE-1
25
25
135
MT/MTZ032 JF-1
25
20
100
MT/MTZ036 JG-1
25
20
100
MT/MTZ040 JH-1
35
20
100
MT/MTZ044 HJ-1
30
15
135
MT/MTZ050 HK-1
30
15
135
MT/MTZ056 HL-1
35
20
200
MT/MTZ064 HM-1
30
25
235