KNF N85.3 - Page 26

Operation Diaphragm pump N85, N86
26 Translation of original Operating and Installation Instructions, english, KNF 121258-121528 01/20
Excessive pressure (with all of the related hazards) can be
prevented by placing a bypass line
with a pressure-relief valve
between the pressure and suctions sides of the pump. For
further information, contact our technical adviser (contact data:
see www.knf.com).
For pumps with AC motor:
WARNING
Automatic starting can cause personal injury and
pump damage
When the operation of the pump is interrupted by the
thermal switc
h, the pump will restart automatically
after cooling down.

Take all necessary care to prevent this leading
to a dangerous situation.
 With the pump at a standstill, open pressure and suction lines
to normal atmospheric pressure.
For pumps with AC motor:
The pump may not start up against pressure or vacuum during
switch
-on. This also applies in operating following a
brief power
failure. I
f a pump starts against pressure or vacuum, it may
block. This activates
the thermal switch, and the pump switch-
es off.
Do not allow the pumps to start against pressure or vacuum. If
you experience a brief power interruption, check for the pres-
ence of p
ressure or vacuum before restarting. If a pump starts
against pressure or vacuum, it may block.
 Install overload switch (see Chapter 7.2)
The life of the diaphragm is prolonged the formation of condensate
is avoided. Therefore the following precautions should be taken:
 Run the pump for a few minutes to warm it up before handling
saturated or nearly saturated vapors.
 KNF recommends: When transferring aggressive media, flush
the pump prior to switch off (see Chapter 9.2.1) to increase the
service life of the diaphragm.
 Restore the system to normal atmospheric pressure (release
pneumatic pressure in pump).
Pump standstill
Switching on the pump
Vapors as media
Switching off the pump /
removing from operation