5.6.6 Connecting the PTC thermistor tripping unit
Pfeiffer Vacuum recommends connecting motors with PTC in the stator winding to a PTC resistor trip-
ping device for protection against overload. Tripping units store the shut-down.
N
L1
M
3
L2
L3
F1 - F3
K1
10
11
AC 220 ... 240 V
Us
F4
U
V
W
S1
S2
k1
K1
H1
S3
2)
A1
A2
T1
T2
Y2
Y1
24
21
22
14
12
11
2)
2)
1)
1)
1)
T1...T3
3)
Fig. 13:
Connection example with PTC thermistor tripping unit
U
S
Control voltage
T1 – T3
PTC resistor sensor
S
1
OFF button
H1
Tripping indicator
S
2
ON button
M
Motor, 3-phase
S
3
RESET button
1)
For devices with two relay outputs only
K1
Contactor
2)
For MSR type (model) only
F1 – F4 Fuses
3)
Only for order no.: P 4768 052 FQ and P 4768 052 FE
Procedure
► After shut-down, switch the tripping unit back on manually via the installed RESET button or via
the external RESET S3.
– Switching on mains detected as automatic RESET.
Installation
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