Wilo Rexa CUT GE Series - Page 138

Appendix en
Installation and operating instructions Wilo-Rexa CUT GE 39
out in an Ex-rated housing (ignition protection class according to DINEN60079-0)!
Non-observance may lead to fatal injury due to explosion! Connection must always be
carried out by a qualified electrician.
▪All monitoring devices outside the “spark-proof areas” must be connected via an in-
trinsically safe circuit (e.g. Ex-i relay XR-4...).
▪The voltage tolerance may not be higher than max. ±10%.
P 13
ATEX approval
•
FM approval
•
CSA-Ex approval
-
Key: - = not available/possible, o = optional, • = as standard
13.3.4.1 Monitoring of motor compart-
ment
The connection is made as described in the “Electrical connection” section.
13.3.4.2 Monitoring of motor winding
DANGER
Risk of explosion due to overheating of the motor!
If the temperature limiter is connected incorrectly, there is a risk of explosion due to
overheating of the motor! Always connect the temperature limiter to a manual re-
activation lock. This means that a “release button” must be manually activated!
The motor is equipped with a temperature limit (1-circuit temperature monitoring). As
an option, the motor can be fitted with a temperature control and limit function (2-cir-
cuit temperature monitoring).
Depending on the version of the thermal motor monitoring, the following triggering
status must occur when the threshold value is reached:
▪Temperature limiting (1temperature circuit):
When the threshold is reached, deactivation with reactivation lock must take place!
▪Temperature control (2temperature circuits):
When the threshold for the low temperature is reached, the motor can deactivate with
automatic reactivation. When the threshold for the high temperature is reached, the
motor must deactivate with reactivation lock!
CAUTION!Motor damage due to overheating! In the event of automatic reactiva-
tion, comply with the specifications for the maximum switching frequency and
switching break!
Connection of the thermal motor monitoring
▪Connect the bimetallic strip via an evaluation relay. Relay “CM-MSS” is recommended
for this. The threshold is preset.
Connection values: max. 250V(AC), 2.5A, cosφ=1
▪Connect the PTC sensor via an evaluation relay. Relay “CM-MSS” is recommended for
this. The threshold is preset.
13.3.4.3 Sealing chamber monitoring (ex-
ternal electrode)
▪Connect the external pencil electrode via an Ex-rated evaluation relay! Relay “XR-4…” is
recommended for this.
The threshold is 30kOhm.
▪The connection must be made using an intrinsically safe circuit!
13.3.4.4 Frequency converter operation
▪Type of converter: Pulse-width modulation
▪Continuous duty: 30Hz up to rated frequency (50Hz or 60Hz). Comply with the min-
imum flow velocity!
▪Min. switching frequency: 4kHz
▪Max. overvoltages on the terminal board: 3000V
▪Output current on the frequency converter: max. 1.5times rated current
▪Max. overload time: 60s
▪Torque applications: quadratic pump curve
Speed/torque curves required are available on request!
▪Observe additional measures with regard to EMC regulations (choice of frequency con-
verter, filters, etc.).
▪Never exceed the rated current or rated speed of the motor.