Honeywell
HP970A, B and HP972B
Pneumatic Humidistats
SERVICE DATA
The
B and
Pneumatic Humidistats
(Humidistats) are nylon element, proportional, two-pipe,
devices used to control humidity in HVAC systems.
The
and B Pneumatic Humidistats control pneumatic
valve and damper actuators in air conditioning systems
requiring humidification and/or dehumidification.
The
is used in systems requiring a reset of relative
humidity as a function of outdoor air temperature, wide
throttling range, or replacement of existing one-pipe
humidistats” A special
model,
013, has all the
necessary adapter fittings to convert older models or
competitors’ humidistats” Figure shows a typical
or
two-pipe hookup. Figure 2 shows a typical
one-pipe hookup.
B
MB
VALVE
SUPPLY
N.C.
Fig. 1. Typical
or
Humidistat
Two-Pipe Hookup.
RESTRICTION
(BLUE)
HUMIDIFIER
VALVE
N.C.
SUPPLY
C3226
Fig. 2. Typical
Humidistat One-Pipe Hookup.
SPECIFICATIONS
Action:
Direct Acting
Reverse Acting
Reverse Acting
Means of Adjustment:
External knob with internally adjustable
locking stops
for minimum and maximum settings
Maximum Safe Pressure:
25
psi
Supply Air Pressure:
13
to
21
psi (90 to
145
18 psi (124
nominal
Copyright 1989 Honeywell Inc. All Rights Reserved 75-7195
Branchline Pressure Indication:
Self-sealing gage tap under the cover