Installation
Testing
Maintenance Instructions
1
Model EST
Electric Solenoid Timer
FEATURES
Input - 120 VAC 5A
Relay Power - 1.1 VA @ 24VAC
Low Voltage Power Supply - 24 VA @ 24VAC
Contact Closure - 3A @ 120VAC
120VAC Output - 3A
24VAC Output - 0.7A
5A Fuse maximum
Intended for use with 24vac solenoid control valve
OPERATION
When backflow relief valve monitor switch is closed for the
time delay, the output relay will trigger, activating alarm light
and latching output relay. Output relay switches 120 VAC
terminals (T1A, T1B), 24VAC terminals (T3A, T3B) and
alarm contact terminals (T5, T7). Turn power off and back
on to reset relay. To adjust time delay turn knob on timer.
Factory set at 10 seconds to avoid nuisance alarms. To test
alarm or check time delay, press and hold TEST switch until
red light comes on. Green light on timer should light when
TEST switch is pressed.
INSTALLATION
Connect 120 VAC input to terminals T10-T12. Connect
backflow relief valve monitor switch to T8 and T9. Connect
a normally closed solenoid shut off valve to T3B and T4.
Connect a normally open solenoid shut off valve to T3A and
T4. The ZW206 solenoid shut off valve will turn the water
supply off when the alarm triggers. Terminals T5 - T7 can
be connected to an external alarm panel. T1A and T2 can
be used to power an external high voltage alarm.
OUTPUT
The 120VAC at T1A and T2 is normally open and will
power an external alarm when the relay latches. The 24
VAC output can be used with a normally open or nor-
mally closed solenoid valve to turn off the water to the
backflow.
A normally open valve will provide water during a power
failure. A normally closed valve will turn the water OFF
during a power failure. ZURN WILKINS recommends a 24
volt AC solenoid, but a 120 volt AC solenoid can be used
on terminals T2 and T1A or T1B.
ADJUSTMENT
The time delay is factory set for a range of 1 to 10 seconds.
The adjustment dial on top of the timer can be used to
adjust this delay. Do not remove timer from socket while
power is on.
Model 375MS
with ZW206 Solenoid Control Valve and EST
WARNING!
A solenoid shutoff valve should not be installed on a
system that must be supplied with water at all times (i.e.
hospital, processing plant, etc.) If water must remain on
during a power failure, a normally open solenoid valve
should be ordered.
If the downstream piping is above the backflow preventer,
then a failed 2
nd
check could cause relief valve discharge
to continue draining a system after the supply is off. For
systems with large amounts of water, like a high-rise build-
ing, a single check should be installed after the backflow.
T1A 120 VAC N/O
T2 120 VAC COM
T1B 120 VAC N/C
T3A 24 VAC N/O
T3B 24 VAC N/C
T4 24 VAC COM
T5 N/O
T6 COMMON
T7 N/C
T8 SWITCH
T9 SWITCH
T10 LINE 1
T11 LINE 2
T12 GROUND
POWER
TIMER
TEST
FUSE
POWER LIGHT
ALARM LIGHT
Timer
Electric
Solenoid
12" MIN.
30" MAX.
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:855-663-9876 Fax:805-238-5766
®
www.zurn.com
®
