Kidde Fire Systems Surge Protector P/N 81-CO2MAN-001 Manuale Utente

September 2013

2-30

P/N 81-CO2MAN-001

Figure 2-34.  Explosion Proof Electric and Cable Operated Control Head

The pneumatic control head (Figure 2-35) is a non-electric mechanical device that allows for 

automatic actuation of carbon dioxide cylinders, stop valves, and directional valves by means 

of pressure pulses transmitted from heat-actuated detectors (HADs) via copper tubing. These 

control heads can also be remotely activated using a cable attached from the control head to 

a cable operated manual pull station. The control heads are also equipped with a manual lever 

for emergency local operation.

Pneumatic control heads operate on the rate-of-temperature-rise principle. This means that a 

sudden increase in the temperature must occur to cause the control head to operate.

The control head must be used in conjunction with a pneumatic heat detection system (rate-

of rise) and operates as follows: A pneumatic HAD is connected to the control head by copper 

tubing. As the temperature changes, the pressure within the detector varies. If the pressure 

increases rapidly, as in the event of fire, a diaphragm in the pneumatic control head will trip a 

lever mechanism, causing the control head to operate. The pneumatic control head is fitted 

with a vent so that slight changes in pressure due to normal changes in ambient temperature 

can be vented to atmosphere. The sensitivity of the pneumatic control head is determined by 

the internal pressure required to trip the control head lever. This pressure is called the setting 

and is measured in inches of water. Vent sizes are rated in terms of the time (in seconds) 

required to relieve two inches of water column pressure in the diaphragm chamber. The higher 

Table 2-10. Explosion Proof Control Head

WK-897494-000

Explosion Proof

24 Vdc

1.65 continuous

33.0 Watts

SET

RELEASED

T

O
RESET

USE

SCREWDRIVER

FOR

MAINTENANCE

SEE

INSTRUCTIONS

CABLE

PULL

ELECTRIC

CONTROL

HEAD

P

A

R

T

NO.

MADE

IN
U.S.A.

KIDDE-FENW

AL,

INC.

400

MAIN

STREET

ASHLAND,

MA

01721

VOL

T

S

HZ

AMPS