Watson-Marlow 620U - Manual (Page 81)

Watson-Marlow 620UN, 620U, 620SN, 620S User Manual 81
UN, U, SN, S
Pumphead
use is
independent
of drive
ingress
protection.
No reference
to ingress
protection
rating or
drive model
(620UN,
620U,
620SN,
620S) is
made
throughout
the
pumphead
sections of
this manual.
26 620RE MarkII, 620RE4 MarkII
and 620R MarkII pumpheads
Note: MarkII pumpheads differ from MarkI pumpheads as follows: they have a new
guard-switching arrangement which is not compatible with 623/624 drives.
Similarly, older guards are incompatible with 620 drives. Elsewhere in this manual,
the term “MarkII” is omitted.
26.1 620RE, 620RE4 and 620R
key safety information
Before opening the pumphead guard please
ensure that the following safety directions are
followed.
For close-coupled drives, ensure that the pump is isolated from mains voltage.
Ensure that there is no pressure in the pipeline.
If a tube failure has occurred, ensure that any product in the pumphead has
been allowed to drain through the controlled waste to a suitable drain.
Ensure that protective clothing and eye protection are worn if hazardous prod-
ucts are being pumped.
26.2 620RE, 620RE4 and 620R
safe-guarding
Primary safety on 620 series pumps is provided by the tool-lockable pumphead
guard. Secondary (backup) protection is provided in the form of an electrical
guard switch which stops the pump if the pumphead guard is opened. The
electrical guard switch on cased pumps should never be used as primary
protection. Always disconnect the mains power supply to the pump before
opening the pumphead guard.