Operating instructions

Page 1
Introduction
The Castle GA902 instrument is designed to provide a visual warning of high
noise levels requiring some form of action.
In its standard form the sign is blank when OFF and clearly visible as an
illuminated message when ON.
Normally when illuminated the sign informs the viewer ‘Approved Hearing
Protection Must Be Worn’. Other message may be supplied to special order.
It is a design feature of the GA902 that the message can only be read when
the high noise level activates the device, reinforcing the message sign.
The GA902 which is readable in all conditions is available in four versions: -
GA902 Master 240V/110V
GA902A Slave 240V/110V
GA902SS Stainless steel 240V/110V
GA902SSA Stainless steel slave 240V/110V
All units are sold as 240V or 110V which must be specified at the time of
ordering.
The Slave units are lamp assemblies which are driven from the master
unit(s).
Instrument Description
The instrument is essentially a standard sound level meter which drives a trip
circuit to provide a switch function at a chosen level.
The switch activates the fluorescent light so illuminating the warning
message.
After the noise level falls below the chosen trip level the light is extinguished
after the preset delay time.
Power is provided by the normal mains source and is housed in a tough metal
case similar to the normal EXIT type sign. It is simply either screwed to the
location point or may be hung using the hooks provided on the top of the unit.
The microphone is fitted within the unit.