TECHNICAL DATASHEET
ALARM LATCH RELAY
TYPE ALR2
Alarm status unaffected by power
cycling or power outages
DIN rail mounting – compact size
Low current consumption
Individual ‘set’ and ‘reset’ inputs
Wide operating voltage range
Power up timer eliminates logic race
conditions
2 change over and one normally open
output contact sets
DESCRIPTION
The Alarm Latch Relay type ALR2 is a compact DIN
rail mounting bi-polar latching relay capable of
maintaining its state through power outages. The
ALR2 is particularly useful in gas monitoring systems
where the gas alarm status must be maintained
through a power outage for safety reasons. In this role
the ALR2 prevents inadvertent dangerous gas alarm
resets.
The Alarm Latch Relay has three sets of voltage free
latching output contacts for use in alarm circuits. The
relay state is controlled by two momentary inputs, one
to set or latch the relay, the second to reset or unlatch
the relay.
The ‘set’ input is typically connected to the gas alarm
signal, while the ‘reset’ input is typically connected to a
deputy key operated switch, allowing alarms to be
acknowledged and reset under controlled conditions.
The ALR2 is fitted with front panel state indication
LEDs, a green ‘armed’ LED which is illuminated when
the ALR2 relay is in the reset state and a red
‘unacknowledged alarm’ LED which is illuminated
when the ALR2 relay is in the latched state. Indication
outputs are provided to drive external remote mounted
LEDs.
The ALR2 is provided with a power up delay to ensure
that the inputs are stable before power is applied to
the latch relay, this prevents logic-race conditions from
producing false alarms during gas monitoring system
power up.
The ALR2 voltage free relay output contacts are Exi
segregated from the power and input circuits to a
value of 30 volts allowing easy integration of the ALR2
output contacts into alarm circuits that are separate
intrinsically safe circuits.
The ALR2 is available in a monostable configuration
where it operates as a conventional intrinsically safe
relay with three sets of voltage free output contacts.
CERTIFICATION
The Alarm Latch Relay type ALR2 is IECEx certified
for use in group I hazardous areas under certificate
IECEx TSA 07.0028X Ex ia I.
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TECHNICAL DATASHEET 149-002-26-xx02-02
WEB
www.austdac.com.au
ALARM LATCH RELAY TYPE ALR2
PART OF THE HUBBELL HARSH AND HAZARDOUS GROUP
SPECIFICATION
GENERAL
ALARM INPUT
Name
Alarm Latch Relay
Input type
Active low
Type
ALR2
Uo
16.5Vdc
Mounting
Io
1.737A
Ui
0V
Mass
DIN rail TS35
45mm (W) x 75mm (H) x 52.5mm (D)
(1.77" (W) x 2.95" (H) x 2.07" (D))
110g (0.24lbs)
Co
11uF
Electrical connections
Cage clamp terminals
Lo
50uH
Maximum conductor size
2.5mm2
Lo/Ro
65uH/Ω
Ingress protection
IP20 (NEMA Type 1)
Ci
0.178uF
Operating Temperature range
20oC to 40oC (-4oF to 104oF)
Li
0uH
Size
EXTERNAL LED OUTPUTS
POWER SUPPLY
Uo
16.5Vdc
Operating voltage range
10 - 16.5Vdc
Io
37mA
Quiescent current
10mA
Co
11uF
Input asserted
70mA @ 16.5Vdc
Lo
50uH
Input asserted
55mA @ 12.0Vdc
Lo/Ro
60uH/Ω
Ui
16.5Vdc
Ui
0V
Ii
3A
Ci
0uF
DIMENSIONS
2 N /O
2 N /C
2 C /O
3 N /O
3 C /O
1 C /O
1 N /C
1 N /O
CONNECTION DIAGRAMS
RELAY OUTPUT CONTACTS
AR MED
UN ACK'D ALA RM
LATCH
11 12 13 14 15 16 17 18
8
7
Uo
0V
Ui
30Vdc
Ii
1.0A
Ci
0uF
Li
0uH
AL ARM L ATC H RE LAY
TY PE: A LR-2
IEC Ex T SA 07 .0028 X
Ex ia I Ma
Ne mko 1 0ATE X106 1X
Ex I M1 E x ia I CE
6
5
4
3
2
1
AL ARM C ONT ACT
RE SET C ONTA CT
RE D ALA RM L ED
GR EEN R EAD Y LED
ORDERING DETAILS
+V E
I.S . POW ER
SU PPLY 1
-VE
DESCRIPTION
ORDER CODE
ALARM LATCH RELAY TYPE ALR2
RLY0058
AUSTDAC PTY LTD
HEAD OFFICE: CASTLE HILL AUSTRALIA
MACKAY QLD AUSTRALIA BRANCH
NORTH AMERICA BRANCH
STAFFORDSHIRE UK BRANCH
WEB
www.austdac.com.au
+61 (0) 2 8851 5000
+61 (0) 7 4955 2777
+1 888 254 9155 (Toll Free in US and Canada)
+44 (0) 1283 500 500
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TECHNICAL DATASHEET 149-002-26-xx02-02