Amarex KRT series, Installation And Operating Manual, Page: 42 / 124

5 Installation at Site
42 of 124
Amarex KRT
Pump sets without cooling system (installation type S)
The pump set features double monitoring of the winding temperature. Two bimetal
switches (terminals 21 and 22, max. 30 V~/2 A) serve as temperature control devices
which open when the winding temperature is too high.
Tripping must result in the pump set cutting out. Automatic re-starting is permissible.
For nonincendive pump sets, the three additional, series-connected (PTC) thermistors
with terminals 10 and 11 must be used. They must be connected to a thermistor
tripping unit with manual reset.
Resistance thermometer (Pt100)
As an option, in addition to the above, the motor can be fitted with resistance
thermometers (Pt100) in the winding. These can be used for reading the motor
temperature (sensor circuit maximum 6 V / 2 mA).
CAUTION
Temperature monitoring not properly connected
Winding damage!
▷ Never use the resistance thermometers as a sole means of monitoring the
motor temperature.
5.4.1.4.2 Leakage inside the motor
DANGER
Incorrect monitoring of leakage electrode
Explosion hazard!
Danger of death from electric shock!
▷ Voltages must be < 30 V AC and tripping currents < 0.5 mA.
PE
K 1
9
K 1
9 8
Position of the electrodes in the
motor housing Wiring of the electrode relay
(standard) Wiring of the electrode relay (pump
sets with vibration sensor only)
Electrodes fitted inside the motor monitor the winding and connection space for
leakage. Both electrodes are connected in parallel (core identification 9). They must
be connected to an electrode relay. Tripping of the electrode relay must result in the
pump set cutting out.
The electrode relay (K1) must meet the following requirements:
▪
Sensor circuit 10 to 30 V AC
▪ Tripping current ≤ 0.5 mA