External Feedback Pressure Connection (4195Kb Series Controllers Only); Vent - Fisher 4195 KB Series Instruction Manual

4195KA, KB, and KC Series
External Feedback Pressure Connection
(4195KB Series Controllers Only)
When a secondary controller in an override application
has this option, reset windup is minimized in the sec-
ondary controller. Connect the external feedback con-
nection of the secondary controller to the output of the
customer-supplied high or low select relay (see figures
2–5 and 4–9).

Vent

WARNING
If a flammable, toxic, or reactive gas is
to be used as the supply pressure me-
dium, personal injury and property dam-
age could result from fire or explosion
of accumulated gas or from contact with
a toxic or reactive gas. The controller
case and cover assembly do not form a
gas-tight seal, and when the assembly
is enclosed, a remote vent line, ade-
quate ventilation, and necessary safety
measures should be used. However, a
remote vent pipe alone cannot be relied
upon to remove all hazardous gas. Vent
line piping should comply with local
and regional codes and should be as
short as possible with adequate inside
diameter and few bends to reduce case
pressure buildup.
2–4
CAUTION
When installing a remote vent pipe, take
care not to over-tighten the pipe in the
vent connection. Excessive torque will
damage the threads in the connection.
If a remote vent is required, the vent line must be as
short as possible with a minimum number of bends
and elbows. Vent line piping should have a minimum
inside diameter of 3/4 inches (19 mm) for runs up to
20 feet (6.1 meters) and a minimum inside diameter of
1 inch (25 mm) for runs from 20 to 100 feet (6.1 to
30.5 meters).
The vent must be protected against the entrance of
any foreign material that could plug it; or if a remote
vent is not required, the vent opening in the case must
be protected against the entrance of any foreign mate-
rial that could plug it. Check the vent periodically to be
certain it is not plugged.