Electrical installation
9.1 Supply voltage connector
9.1.1 Mains voltage
Parallel connection to inductive con‐
sumers
28
CAUTION!
Bonding of the contacts of your switching relay
The high starting current can cause the contacts of the
on-site switching relay to bond together if the mains
voltage switches a solenoid metering pump on and off in
a process.
–
Use the switching options offered by the external
socket to control the pump (functions: Pause, Auxil‐
iary frequency or Operating modes: Contact, Batch,
Analogue).
–
Use a starting current limiter if it is impossible to
avoid switching the pump on and off via a relay.
Personnel:
n
Install the pump in line with best working practice and in accordance
with the operating instructions and applicable regulations.
WARNING!
Unexpected start-up is possible
The pump can start pumping and consequently feed
chemical may escape as soon as the pump is connected
to the mains/power supply.
–
Avoid the escape of feed chemical.
–
If you have not done so, immediately press
[STOP/START] or disconnect the pump from the
mains voltage e.g. using an Emergency Stop switch.
–
Refer to the material safety data sheet for your feed
chemical.
CAUTION!
If the pump is integrated into a system: Design the
system so that potential hazardous situations are
avoided by pumps starting up automatically subsequent
to unintended power interruptions.
CAUTION!
Provide an option to disconnect the pump from the
mains/power supply without Emergency Stop switch.
Should the pump be connected to the mains in parallel to inductive con‐
sumers (e.g. solenoid valves, motor), the pump must be electrically iso‐
lated when these consumers are switched off.
Supply the pumps with voltage via a contactor relay or relay using
n
separate contacts for the pump.
If this is not possible then connect a varistor (part no. 710912) or an
n
RC member, 0.22 µF / 220 Ω in parallel.
Electrician