Hochiki CHQ-ISM/DIN User Manual
Hochiki Audio accessories
Hochiki Europe (UK) Limited
2-3-0-1469/ISS1/SEPT13
HOCHIKI INTRINSICALLY SAFE COMPATIBLE SOUNDER CONTROL
MODULE INSTALLATION INSTRUCTIONS
Products covered: CHQ-ISM, CHQ-ISM/DIN and CHQ-ISM(HFP)
Function
The CHQ-ISM is a Sounder Control module which interfaces between the Hochiki Analogue system via a
CHQ-
DSC or conventional sounder O/P’s and the intrinsically safe sounder/beacon units via an intrinsically
Safe barrier. The module provides line monitoring for Open or short circuits on the wiring connected to both
the Safe and Hazardous areas. The unit is externally powered with 24V and provides a Fault monitoring I/P
which can be used to indicate something like a mains failure back to the CIE on SNDR CCT1.
NOTE: This sounder interface module should always be used with an I.S. Barrier. The CHQ-ISM is not itself
intrinsically safe.
Specification
Parameter
Quantity
Units
Notes
Min
Typ.
Max
PSU Supply voltage
20
24
28
V
I.S. BARRIER1 voltage
20
-
28
V
I.S. BARRIER2 voltage
20
-
28
V
Quiescent Current
-
-
50
mA
Excluding current drawn by SNDR
EOL’S and IS BARRIER Device loads.
SNDR CCT1 Current powered
with 24V
-
12
15
mA
Does not include current possibly
drawn by SNDR EOL1 (e.g. add 24 mA
if using a 1k EOL resistor)
SNDR CCT2 Current powered
with 24V
12
15
mA
Does not include current possibly
drawn by SNDR EOL2 (e.g. add 24 mA
if using a 1k EOL resistor)
I.S. BARRIER 1 Load current
-
-
40
mA
Actual value dependant on IS sounder
used.
I.S. BARRIER 2 Load current
-
-
40
mA
Actual value dependant on IS sounder
used.
Maximum Cable Resistance on
I.S. barrier terminals
-
-
25
R
This is the combined total Wiring
resistance between the IS Barrier
Terminals and the IS device.
EOL CCT1
User Determined
Hochiki CHQ-DSC module uses a 1K
EOL CCT2
User Determined
Hochiki CHQ-DSC module uses a 1K
Monitored input EOL
10 K
resistor
10 K
± 5% 0.4 W
Input Thresholds
9.5
10
10.5
K
Normal condition (10 K
)
100
-
-
On/Activated (>100 K
-
-
50
On/Activated (<50
Table 1