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Installation

Crowcon Gasmaster

2.1 Before installation

Before carrying out any installation work,
ensure that local regulations and site proce-
dures are followed. Further advice is avail-
able from Crowcon if required.

Gasmaster is intended for use in non hazardous
areas. Gas and fire detectors may be mounted in
potentially flammable atmospheres using appro-
priate barrier devices where necessary. Check the
equipment to be installed is suitable for the area
classification. Please refer to instrument installa-
tion manuals for information on location.

Crowcon recommends the installation of
Gasmaster be carried out by people with experi-
ence of installing electrical equipment in poten-
tially hazardous areas.

2.2 General

This section describes how to get started with a

Gasmaster 4

Gasmaster 1

system that has been

pre-configured for the detectors supplied. Figures
2.1, 2.2 and 2.5 show the internal structure of
Gasmaster.

See the

Specification and Inspection Certificate

provided with your system for full details of its
configuration.

Figure 2.1 shows the internal arrangement of a
Gasmaster system. The front cover



is removed

by unscrewing the four screws



and carefully

disconnecting the two-pole sounder connector
from the display PCB



. The front cover can either

be supported by the case using one of the retain-
ing screws, or removed completely and placed in
a safe location. Two separate chassis support the
display PCB and batteries which supports the
display PCB



and batteries



. The terminal PCB



contains the input modules, and all of the input

and output terminals. The display PCB



is con-

nected to the terminal PCB



via a 50-way ribbon

connector, and is hinged on the left side so that it
can be moved to provide access to the detector
input terminals. Most terminals are accessible
once the display PCB is moved and the batteries
are removed. If necessary the two chassis can be
removed for easier terminal access. In order to
remove the display chassis, the display PCB ribbon
connector must first be carefully un-plugged.
Care should be taken when re-fitting the display

PCB so as not to damage the connector or ribbon
cable.

Six punched cable gland knock-outs are pro-
vided on the top and bottom of the enclosure.
The knock-outs are suitable for M20, 1/2"NPT
or PG13.5 cable glands. To remove Knock-outs,
tap around the edge of the recessed flange using
a small hammer and a screwdriver. The knocks
outs should then come away from the enclosure.
Knock-outs should be removed prior to mounting
Gasmaster and great care must be taken to avoid
damaging internal components.

Power supply

Gasmaster comes fitted with an auto-ranging
power supply suitable for 100-240 V ac 50-60 Hz
operation. This provides a nominal 24 V dc supply
with a maximum power of 60 W. Alternatively
Gasmaster can be powered from an external 24
V dc supply, a maximum 60 W supply is required.

Gasmaster must never be connected to ac
and dc supplies at the same time.



Front cover







Display
PCB



Batteries



Chassis plate

