22May2002
Page
12
below alarm set point, relay automatically resets to original state.
Latching:
when alarm set point is reached and exceeded, relay is activated (i.e. open
contacts close and closed contacts open). When gas concentration falls
below alarm set point, relay does
not
reset to original state. The relay
must be manually reset using a switch.
Energized:
Power is normally applied to relay such that normally open contacts are
closed and normally closed contacts are open. When the alarm set point is
reached or exceeded, the relay changes to the power down state.
Non- Energized:
Power is normally
not
applied to relay such that normally open contacts are
open and normally closed contacts are closed. When alarm set point is
reached or exceeded, the relay changes state.
VII.
Rain/Splash/RF Shield (Optional)
A black anodized aluminum shield offers protection to the sensor from rain, splashing,
radio frequency (RF) and mechanical shock.
The upper portion of the housing is provided with internal and external 3/4” NPT threads.
The external threads screw into the explosion-proof junction box which houses the
remote amplifier. The sensor screws into the 3/4” NPT internal threads.
The lower portion of the housing consists of a cylinder with bottom plate; the housing is
perforated to allow gas entry. The cylinder is secured to the upper housing with four set
screws.
Install the shield as follows:
1.
Screw upper portion of housing into junction box.
2. Carefully guide brown sensor cable connector through housing
into junction box. Screw sensor into housing hand tight. Attach
sensor connector to bottom of main circuit board at connector
marked
SENSOR
. Seat the sensor connector fully to lock in place.
