2 … 6
GAO-A2…
SPDT pressure switch requires no auxiliary power to actuate. The GAO-A2… is suitable for making and/or
breaking a circuit when the set point is exceeded or undershot. A tripped switch is indicated by a neon light after set point
is exceeded or undershot. Automatic reset when pressure returns below or above set point.
GMH-A2…
SPDT pressure switch requires no auxiliary power to actuate. The GMH-A2… is suitable for making and/or
breaking a circuit when the set point is exceeded. A tripped switch is indicated by a neon light after set point is exceeded.
Manual reset is required to reset the switch.
GML-A2…
SPDT pressure switch requires no auxiliary power to actuate. The GML-A2… is suitable for making and/or break-
ing a circuit when the set point is undershot. A tripped switch is indicated by a neon light after set point is undershot.
Manual reset is required to reset the switch.
GMH (Operating state shown)
As pressure rises
, 2 NO closes, 1
NC opens, and Neon light ON (fault),
switch trips and locks out.
Specifications
Max. operating pressure
Pressure connection
Temperature range:
For series ending in -2,-3,-5, and -6
For series ending in -8
Materials
Electrical ratings
Nominal current
Electrical connection
Enclosure rating
Setting tolerance
Vent Limiter
GAO-A2-4-2,3,5,6
7 PSI (500mbar)
GMH- and GML-A2-4-4,6
7 PSI (500mbar)
GAO-, GMH- and GML-A2-4-8
14 PSI (1000 mbar)
O ring flange connection on underside of pressure switch
Ambient temperature
-40 °F to +140 °F (-40 °C to +60 °C)
Medium temperature
-40 °F to +140 °F (-40 °C to +60 °C)
Ambient temperature
-22 °F to +140 °F (-30 °C to +60 °C)
Medium temperature
-22 °F to +140 °F (-30 °C to +60 °C)
Housing
Aluminium
Switch
Polycarbonate
Diaphragm
NBR-based rubber
Switching contact
Silver or Gold
AC eff.
min. 24 V max. 240 V
DC
min. 24 V max. 48 V
Silver (Ag) contact ratings
Gold (Au) contact ratings
AC 10A resistive @ 120 VAC
AC 8A inductive @ 120 VAC
DC min. 20mA @ 24 VDC
DC max. 5mA @ 5 VDC
DC max. 2A @ 24 VDC
DC max. 20mA @ 24 VDC
Screw terminals via 1/2” NPT conduit connection
NEMA Type 4
±15% switching point deviation referred to set point. Adjusted as pressure rises or
as pressure falls, vertical diaphragm position.
Incorporates a vent limiter as per UL 353 and limits the escape of gas less than 1.0
CFH of natural gas at 7 PSI if internal switch diaphragm ruptures.
GML
(
Operating state shown)
As pressure falls
, 2 NO opens, 1
NC closes, Neon light ON (fault), switch
trips and locks out.
GAO (Shown as a high gas limit)
As pressure rises
above set point,
1 NC opens, 2 NO closes, Neon light
ON (fault).
As pressure falls
below
setpoint, switch resets: 1 NC closes
and 2 NO opens.