GMX Series Time Controls
Application
The GMX Series are universal electromechanical time
switches within UL TYPE 1 indoor enclosures or UL TYPE
3R outdoor enclosures intended for the control of lighting,
heating, air conditioning, pumps, motors, or general
electrical circuits in residential, commercial, industrial and
agricultural facilities. Basic models are:
GMX
GMX
GMX
GMX
ST
SW
QT
QW
SPDT
SPDT
SPDT
SPDT
24 hour synchronous drive
7 day synchronous drive
24 hour quartz drive
7 day quartz drive
Specifications
Switch Rating: SPDT Switch
21A Resistive @ 125/250 VAC
1 HP @ 125 VAC
2 HP @ 240 VAC
1350W Tungsten @ 240 VAC
675W Tungsten @ 120 VAC
Environmental Ratings
Ambient Temperature: –40°F to 180°F synchronous drive
–20°F to 140°F quartz drive
Humidity: 0-95% RH, Non-condensing
Wiring Connections
Screw clamp terminals for up to AWG #10 wires.
Agency Approvals: UL Listed
Installation
1.Select knockouts to be used. Remove the inner (1/2”)
knockout by inserting a screwdriver in the slot and
carefully punch knockout loose. Remove slug. If the 3/4”
knockout is required, remove the outer ring with pliers
after removing the 1/2” knockout. Smooth edges with a
knife if necessary.
2.Place enclosure in desired mounting location and mark
the three mounting holes.
3.Drill holes for #10 screws, start screws in holes.
4.Place enclosure over screws and tighten screws.
5.Connect conduit hubs to conduit before connecting the
hubs to the enclosure. After inserting hubs into enclosure,
carefully tighten hub lock nut. Do not over-torque.
6.Wire in accordance with National and Local Codes.
GROUNDING: This enclosure is of plastic construction and
does not require a ground connection and does not require
bonding in pool applications.
This enclosure does not provide grounding between
conduits. When using non-metallic conduit or cable, connect
the ground wires of all cables together with a twist on wire
connector. When metallic conduit is used, use grounding
type bushings and a jumper wire between each conduit.
GMXST-I-120
Programming Instructions
Setting the time: TO SET THE CURRENT TIME
(AND DAY OF WEEK ON 7 DAY UNITS), TURN THE
MINUTE HAND CLOCKWISE. DO NOT SET THE TIME BY
ROTATING “OUTER” DIAL.
Programming: The 24 hour model has trippers of 15
minute increments, and a AM/PM indication on the outer dial.
The 7 day model has trippers of 2 hour increments, and the
outer dial shows the 7 days of the week and AM/PM for each
day. Push the captive trippers outward for the time period(s)
that the load is to be on (Normally open contacts closed).
Manual Override: With the manual switch in the middle
position, the time switch is in automatic mode and will switch
at the programmed times. In the upper position “I”, the load
is permanently ON. In the lower position, “O”, the load is
permanently OFF.
BATTERY POWERED RESERVE (Quartz Models): In
case of power failure, the built-in nickel-cadmium battery
maintains the time of day for a minimum of 7 days.
Typical Wiring Diagrams
120V
Timer,
120V
120V Timer and Load
120V
Timer
andLoad
Load
41
3
2
T
T
52
3
4
5
1
2
3
41
T
52
3
4
5
1
2
3
41
TIMER
T
TIMER
NC COM NO NC TIMER COM NO
TIMER COM NO
NC COM NO NC TIMER L1COM NO
H
L1
H
H
H
TO LOAD
TO 208/240V LINE
TO LOAD
TO LOAD TO 120V
LINE
LINE TO 120V LINE
TO LOAD TO 208/240V
TO 120V LINE TO 120V LINE
TO
N
N
L2
N
L2
N
nd Load
Enclosure Dimensions
120V Timer,
24V,
120V,
or 240VLOAD
Load
120V
Timer
24-240V
120V
TWO
SPEED
FAN
120Vand
TWO
SPEED FAN
208/240V Timer and Load
120V Timer 24-240V LO
120V Timer
Load
T
T
T
T
T
T
4
1
3
2
5
4
1
3
4
1
3
2
52
4
4
1 5 2
3
1
3 COM
2TIMER
5
5NO NC
O NC
H
TIMER
COM
NO
NC
TIMER
COM
NO
NC
TIMER LOW
COM NO NC
TIMER COM NO NC LOAD LOW
TO LOAD TO 120V
LINE
H
L1
H
H
HIGH
HIGH
TOLINE
24-240V LINE
120V
120V LINE TOTO
N TOLINE
COM
TO LOAD
TO 208/240V
LINE
LOAD
COM
TO 120V
N
N
N
L2
5
1
3
2
TIMER
H
TO 120V LINE
N
120V
Two
SpeedFAN
Fan
120V
TWO
SPEED
T
1
2
TIMER
H
TO 120V LINE
N
3
4
5
COM NO NC
LOW
HIGH
COM
INTERMATIC INCORPORATED
Spring Grove, IL 60081-9698
www.intermatic.com
4
5
COM NO NC
LOA
TO 24-2
158--00760
4
T
T
1
Timer,
Load
208/240V
Timer and
Load 120V Timer 24-240
1
208/240V 208/240V
Timer and
Load 208/240V