© 2014 Alarmtech
GD335 manual 1410en
Page
1
of
2
Detectors
Passive glass break detector
Instruction manual
GD 335
DESCRIPTION
GD 335 is a passive glass break detector glued on the glass
surface. The detector is designed in the form of two-ter-
minal component. It has to be connected to Control and
Indication Equipment (CIE) or another specialized inter-
face unit like IU 300, in alarm loop configured as EOL/NO
(End-Of-Line – Normally Open).
EOL resistor has to be placed at the end of the alarm loop
providing continuous analogue communication with CIE
drawing fixed value of current.
The detector has high resistance in normal state and does
not draw any current from EOL loop. It has a latching cir-
cuit lowering rapidly its internal resistance during alarm.
Increase of current consumption from EOL loop is signal-
ling intrusion to CIE.
It is specifically designed for surveillance of:
shop-windows
glass sliding doors
single-glazed windows
other vulnerable glass surfaces in public offices and
private homes.
GD 335 complies with:
EN 50131-2-7-2:2012, security grade 2
EN 50130-5:2011, environmental class IIIA
FEATURES
Detects glass break of float glass
Large coverage area
Very resistant to disturbances on the glass
No sensitivity adjustment
Ideal for 24-hour loop perimeter protection
Leads are polarity independent
Low current consumption
Completely sealed plastic casing
OPERATING PRINCIPLE
GD 335 is equipped with a piezoelectric sensor that de-
tects mechanical waves propagating in the glass pane.
During glass breakage, a very short vibration pulse with
high amplitude and very high frequency contents is gen-
erated and propagates with high speed in the glass. This
pulse triggers the detector, changing its voltage/current
characteristics.
Detector has high resistance in normal state and
practically does not draw current from EOL loop
Detector draws maximum of 7.5 mA in alarm state
from EOL loop signalling intrusion to CIE
WIRING
# Signal
Wire colour code
Function
Description
1 a1
White
Terminal a: (-) or (+)
Terminal a (a1, a2 - shorted)
2 a2
White
Terminal a: (-) or (+)
3 b1
White
Terminal b: (+) or (-)
Terminal b (b1, b2 - shorted)
4 b2
White
Terminal b: (+) or (-)
Wire identification hints:
Shorted wires are marked with an additional small label
Shorted lines be also easily identified with the help of ohm-meter, as both pairs consist of 2 wires shorted inside
detector
CIRCUIT DIAGRAM
GD 335
a2
b2
a1
b1
