Honeywell VP525C, Engineering Manual, Page: 70 / 228

Relays
62 customer.honeywell.com 70-6925
RP975 Pneumatic Hesitation Relay
A three-port hesitation relay provides minimum outside air damper
position plus controlled ventilation for large volume unit
ventilators. Replacement devices are available for Johnson,
Powers, and Barber-Colman devices.
• Manually adjustable minimum position. In-line, wall or panel
mounted.
• Sharp-barb air connections.
• Molded plastic construction.
Typical Piping With Isolation Circuit
Type: Pneumatic Three-Port Hesitation relay
Dimensions, Approximate: 2 1/4 in. high x 2 1/2 in. wide x 3 3/4 in.
deep (57 mm high x 63 mm wide x 96 mm deep)
Airflow Usage: 0.022 scfm (10 mL/s)
Air Connections: Barb fittings 5/32 in. (4 mm) O.D. plastic tubing
Capacity: 0.003 scfm (1.65 mL/s)
Knob Rotation: Knob has two (2) internal breakaway stops that limit
rotation to 188 degrees. Each stop, when removed, adds 56 degrees
of rotation. Maximum rotation is 300 degrees.
Mounting: Wall or In-line or panel
Operating Humidity Range (% RH): 5 to 95% RH
Temperature Range: 32 F to 125 F (0 C to 52 C)
Maximum Safe Operating Pressure: 30 psi (205 kPa)
Replacement Parts:
14003203-003 Conversion Kit to convert Johnson, Powers,
Robertshaw, Barber Coleman and older Honeywell switches
Pneumatic Relay Accessories and Replacement Parts
M
B
M
2
1
3
RP975A
M
DA
THERMOSTAT
LOW LIMIT
SENSOR
5
3
2
RP470B
ISOLATE PILOT
WITH RP470B
PIPED AS
REPEATER
C4473
HEATING VALVE
OR FACE AND
BYPASS DAMPER
0.005 IN. RESTRICTION
EXH
DAMPER
ACTUATOR
Product Number Operation Description Includes
RP975A1003 Provides minimum outside air
damper position
Pneumatic Three-Port
Hesitation Relay
14003030-001, 1 1/2 in. Mounting Clip for mounting relay to wall or
panel. Also includes scaleplate and knob, factory mounted and
calibrated. Use with MP909 or MP918 Damper Actuator having a 7 to
13 psi (50 to 90 kPa) spring range
Product Number Description Used With
14003030-001 Mounting Clip RP470, RP471, SP970
14003638-001 Bag Assembly, Mounting Hardware for RP418 RP418;
315178/0062 Cup, feedback spring for old Gradutrol relay —;