Specifications

Halogen Gas Monitor – Multi Zone
8 Instruction 3015-5074
It should also be noted that refrigerant gas is heavier than air and tends to collect below the point of a leak.
Therefore a sample taken near the floor will have a greater concentration of gas than that collected above the
source of a leak. Therefore, sampling points should be located as close as possible to the sources of potential
leaks. If this is impractical, then the alarm set points should be adjusted for that zone to compensate for the
dilution of the refrigerant gas. Sample inlet filters should be mounted 12-18” above the floor. DO NOT block
any of the zones. Unused zones may be disabled by setting the distance parameter to zero feet in the zone
setup screen.
The HGM-MZ should be centrally located in the mechanical room and be readily accessible for easy visual
monitoring and servicing. The combined length of sample tubing, plus exhaust tubing, should not exceed
1200ft. for any zone. The fresh air purge line should draw from an area that does not contain any refrigerant
gas. The exhaust line should run to an outside location if possible. The combined length of the purge line
and the exhaust line cannot exceed 300 feet.
Ideally, two to three pick up points spaced around each chiller will provide sufficient coverage. It may be
necessary to perform a “smoke” test of the mechanical room to determine the best locations. The smoke test
would provide the pattern of air currents present in the mechanical room.
HGM-MZ / HGM-RD Refrigerant Gas leak Monitor Mechanical Room Placement
The HGM-RD should be mounted outside of the mechanical room, or just inside the room’s doorway if the first
option isn’t possible. This is the “split architecture design” for safety of the operator. The HGM-RD can be
located up to 4500 feet from the HGM-MZ. The HGM-RD is the man machine interface by which you
program the HGM-MZ, acknowledge alarms and observe conditions inside of the mechanical room. Note that
there are two additional alarm relay contacts in the HGM-RD that can be programmed to alarm with “leak,
spill, evacuate, fault or monitor on”.
HGM-RD
Remote Display
Module outside of
mechanical room
HGM-MZ
Halogen
Gas
Monitor
Outside Hallway
Machine Room
Sample Inlet Pickup Points
Chiller
Exhaust Fan
Sample Inlet
Pickup Point
Auxiliary
Horn/Strobe
Fresh air purge
from area away
from refrigerant
gas