11
Installation and maintenance
LSRPM - PLSRPM
Synchronous permanent magnet motors
LEROY-SOMER
4155 en - 2012.05 / e
Alarm and early warning
All protective equipment can be backed up by another type of
protection (with a different NRT). The first device will then act
as an «early warning» (light or sound signals given without
shutting down the power circuits), and the second device will
be the alarm (shutting down the power circuits).
Protection against condensation: space heaters
Identification: 1 red label
A glass fibre flexible resistor is fixed on 1 or 2 coil end turns.
This resistor heats the machines when stopped and thus
prevents condensation inside the machines.
Power supply: 230 V single-phase unless otherwise specified
by the customer.
If the drain plugs at the bottom of the motor were not removed
at the time of installation, they must be opened approximately
every 6 months.
Warning: the motor may remain powered-up,
depending on the type of protection. Ensure that
the mains supply is disconnected before any work is
carried out in the terminal box or in the cabinet.
Warning: check that the space heaters are
powered down before any work is carried out in
the terminal box or in the cabinet.
Type
Operating principle
Operating curve
Breaking
capacity (A)
Protection provided
Mounting
Number of devices*
Normally closed
thermal protection
PTO
Bimetallic strip
indirectly heated,
with normally closed
(NC) contact
I
O
NRT
T
2.5 A at 250 V
with cos
j
0.4
General monitoring
for non-transient
overloads
Mounting in control
circuit
2 or 3 in series
Normally open
thermal protection
PTF
Bimetallic strip
indirectly heated,
with normally open
(NO) contact
I
F
NRT
T
2.5 A at 250 V
with cos
j
0.4
General monitoring
for non-transient
overloads
Mounting in control
circuit
2 or 3 in parallel
Positive temperature
coefficient
thermistor
CTP
Non-linear variable
resistor,
indirectly heated
R
NRT
T
0
General monitoring
for transient overloads
Mounted with associated
relay in control
circuit
3 in series
Temperature sensor
KT
U
Linear variable
resistor,
indirectly heated
R
T
0
Continuous monitoring
with high accuracy
at key hot spots
Mounted in control boards
with associated reading
equipment
(or recorder)
1 per hot spot
Thermocouples
T
(
T
< 150 °C)
Constantan copper
K
(
T
< 1000 °C)
Copper Copper-nickel
Peltier effect
V
T
0
Continuous monitoring
at regular intervals
at hot spots
Mounted in control boards
with associated reading
equipment
(or recorder)
1 per hot spot
Platinum
temperature sensor
PT 100
Linear variable
resistor,
indirectly heated
R
T
0
Continuous monitoring
with high accuracy
at key hot spots
Mounted in control boards
with associated reading
equipment
(or recorder)
1 per hot spot
- NRT : Nominal running temperature.
- The NRTs are chosen according to the position of the sensor in the motor and the temperature rise class.
* The number of devices relates to the winding protection.
