GasSens
Gas Detection System
Section 1 - Overview
O & M Manual
A14-RK, 8/06
1 - 4
A11 Sensor/Transmitter
Consists of an electrochemical gas sensor closely coupled to a NEMA 4X transmitter. This
component measures gas concentration and converts the measurement to a digital signal for
transmission to a receiver module. It must be mounted in the area where gas leakage or buildup
is expected, and can either be wall mounted or supported by electrical conduit carrying
interconnecting wiring. Sensor/transmitters are available with optional
Auto-Test
, an
electrochemical gas generator which automatically tests sensor response daily and alarms any
sensor problems. For hazardous areas, explosion-proof sensor/transmitters are available.
A14 Receiver Module
Receives digital data from the sensor/transmitter and provides an LED display of gas
concentration, two gas alarm setpoints, three gas alarm relays, an isolated 4-20 mA output, and a
trouble alarm and relay. The receiver is packaged in a compact DIN rail mount housing, and fits
easily into NEMA 4X enclosures suitable for one, two, three, or six modules. Each module is
switch programmable for full scale range, alarm setpoints, relay latch/non-latch operation, and
relay normal/fail-safe operation. A single switch (marked A/R) on the front panel provides alarm
acknowledge and reset functions, and can also be used to test front panel LED indicators and to
inhibit alarm relays. LED bars on the front panel provide visual indication of alarm status.
A17 Power Supply Module
Provides 12 VDC power to one or two receiver modules plus power for an audible horn and
for charging an external battery. Packaged in the same compact DIN rail mount module used for
the receiver, the power supply is designed for use throughout the world. Input to this module may
be any AC (50 or 60 Hz.) or DC voltage between 85 and 270 volts. The supply is self-regulating,
meaning no jumper changes, no changes in switch settings, and no variation in wiring pattern. A
power failure alarm relay is included in the module to signal the loss of input power.
NEMA 4X Enclosures
Four standard enclosures are available for housing receiver and power supply modules.
Polystyrene enclosures are suitable for outdoor environments, and digital displays and alarm
indicators are clearly visible through a clear polycarbonate window on the front. The window
hinges open to gain access to the receiver A/R control switch, and the entire front section of the
enclosure can be removed for ease of mounting and wiring. Enclosures are provided with
knockouts on all four sides to facilitate wiring, and 1/2" FNPT conduit hubs are provided with each
enclosure.
Explosion-proof Enclosures
Two versions are available to allow use of the receiver and power supply modules in
hazardous areas. One version is suitable for a single receiver module, while the second is large
enough to contain both a power supply and a receiver. Enclosures are rated for Class 1, Division
1, Groups C & D. Group B enclosures are also available if required. All explosion-proof
enclosures can be supplied with an external acknowledge and reset switch.