en
Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
13
6.4.6
Dry-running protection
Dry-running protection prevents the pump from being operated
without fluid and air from entering the hydraulics. For this purpose,
the minimum permissible fill level is monitored using an external
control. When the minimum fill level is reached, the pump is
switched off. Furthermore, depending on the control, a visual and
acoustic alarm is triggered.
The dry-running protection can be integrated into existing con-
trols as an additional measuring point. Alternatively, the dry-run-
ning protection can also work as a stand-alone shut-off device.
Depending on the system security, the pump can be restarted au-
tomatically or manually.
Installation of dry-running protection is recommended for op-
timum operational reliability.
6.5
Electrical connection
DANGER
Risk of fatal injury due to electrical current!
Improper conduct when carrying out electrical work
can lead to death due to electric shock!
• Electrical work must be carried out by a qualified
electrician!
• Observe local regulations!
•
Mains connection corresponds to the information on the rating
plate.
•
Power supply on mains side with clockwise rotating field for
three-phase AC motors (3~ motor).
•
Route the connection cables according to the local regulations
and connect them according to the wire assignment.
•
Connect
all
of the monitoring devices and check their function.
•
Secure the earthing in accordance with the local regulations.
6.5.1
Fuse on mains side
Circuit breaker
The size and switching characteristics of the circuit breakers must
conform to the rated current of the connected product. Observe
local regulations.
Motor protection switch
Make provision for an on-site motor protection switch for devices
without a plug! The minimum requirement is a thermal relay/motor
protection switch with temperature compensation, differential
triggering and anti-reactivation device in accordance with the local
regulations. In case of sensitive mains, make provision for the in-
stallation on-site of other protective equipment (e.g. overvoltage,
undervoltage or phase failure relay, etc.).
Residual-current device (RCD)
•
Install a residual-current device (RCD) in accordance with the
regulations of the local energy supply company.
•
If people can come into contact with the device and conductive
fluids, install a residual-current device (RCD).
6.5.2
Maintenance tasks
•
Check the insulation resistance of the motor winding.
•
Check the resistance of the temperature sensors.
6.5.2.1 Checking the insulation resistance of the motor wind-
ing
✓
Insulation tester 1000 V
✓
Motors with
capacitor
: Short-circuited windings!
1.
Check the insulation resistance.
⇒
Measured value at initial commissioning: ≥ 20 MΩ.
⇒
Measured value at interval measurement: ≥ 2 MΩ.
▶
Insulation resistance checked. If the measured values devi-
ate from the specifications, consult the customer service.
6.5.2.2 Test the resistor of the temperature sensor
✓
Ohmmeter available.
1.
Measure the resistance.
⇒
Measured value
Bimetallic strip
: 0 ohms (passage).
▶
Resistance checked. If the measured value deviates from
the specification, consult the customer service.
6.5.3
Connection single-phase AC motor (1~motor)
bn
bu
Cr
C s
M 1~
gn-y
e
U1/Z1
bn
U2 bk
Z2 gy
gn-y
e
L
N
PE
Fig. 6:
Connection diagram 1~ motor
Wire colour
Terminal
Brown (bn)
L
Blue (bu)
N
Green/yellow (gn-ye) Earth
The pump is equipped with a plug (CEE 7/7). Connection to the
mains is established by inserting the plug into the socket (type E or
type F). The plug is not watertight.
Bimetallic strips are installed in the motor in addition to the capa-
citor box for thermal motor monitoring. The motor monitoring is
self-switching. Separate connection is not possible.
If the pump is directly connected to the switchgear, cut off the
plug. Connect the connection cable according to the connection
diagram in the switchgear.