Hydrolevel CGT450 User Manual

Low maintenance. No moving parts to wear stick or hang up,
as in float devices.

CG450 Series
CGT450 Series

Solid state circuitry. Designed for the highest level of perfor­mance and reliability.

Automatically shuts off burner, after delay, in a low water

Low Water Cut-Offs
For Steam Boilers

120 VAC Operating Voltage
Max. Pressure 15 psi

U.S. Patent Nos. 5,739,504 & 6,390,027

condition to prevent dry firing.
Time delay allows water to feed above the probe to a safe

operating level.
INTERMITTENT LEVEL TEST – periodically monitors settled

water level for added protection of today’s smaller steam
boilers.

HOW TO INSTALL

1 2 3

SAFE
WATER
LINE

WARNING – To prevent electrical shock or
equipment damage, power must be off during
installation or servicing of the control. To pre­vent serious burns, the boiler should be thor­oughly cooled before installing or servicing con­trol. Only qualified personnel may install or ser­vice the control in accordance with local codes
and ordinances. Read instructions completely
before proceeding.

The probe may be installed in the boiler above
the lowest safe water level established by the
boiler manufacturer. Most manufacturers pro­vide a suitable opening in the side of the boiler.

1/4"

Allow 1/4" clearance from the probe to any boiler
surface, tube or baffle. NOTE: Excessive use of
Teflon tape to seal probe piping threads may
insulate the control from boiler ground. This
could result in the control not operating.

4

R E M O TE M O U N TE D M O DE L S O N LY

BA

A. To secure mounting plate to boiler jacket,* pre-drill two 3/32" pilot holes using the mount­ing plate as a template. Secure plate with sheet metal screws provided. Attach control to
mounting plate by slipping keyholes in back of chassis over pre-mounted screws on plate.
Tighten screws.

B. Using a wire nut, attach a wire (min 90°C) to the pigtail lead in the control box. Attach the
other end to the probe terminal in the remote probe housing. Attach a second wire between
the ground screw on the control chassis and one of the four screws in the remote probe
housing. Note: Wires and wire nuts not provided.

*Or other suitable surface

83 Water Street
New Haven, CT 06511
Phone: [phone] • FAX: [phone]
www.hydrolevel.com

Loosen the two control cover binding head
screws and remove the cover. Assemble the
chassis to the probe flange and secure with the
screws provided with the probe.

5

Connect the ring terminal wire lead to the probe
terminal stud and secure with the lock washer
and wing nut provided. With the power
removed, proceed with installation and wiring
according to the instructions on page 2. Upon
completion of wiring replace control cover.

HOW TO WIRE

FACTORY
INSTALLED
JUMPER.

DO NOT
REMOVE

BURNER

POWER

SOURCE

120V

AC

+

0

LIMIT

CONTROLS

AP2P112

BURNER

WATER

FEEDER

MODEL CG450

1

Connect input voltage (120 VAC,
60 HZ) to terminals 1 and 2.

2

Connect terminal 2 to burner circuit
neutral. Connect terminal P2 to
burner Circuit in series with other
limit controls. Consult boiler manu­facturer instructions for proper ter­minal connections. Control should
be wired in series with and before
other limit controls.

3 4

Optional water feeder connection.
Connect feeder N to terminal 2.
Connect Feeder H to terminal 1.
Connect feeder “FEED” or “W” to
terminal A. For water feeders with
2 leads, connect feeder neutral
to terminal 2 and feeder hot to ter­minal A. Note: Use of a solenoid

valve or McDonnell & Miller Model
101A water feeder may cause
flooding and is not recommended
for use with this low water cut-off.

MODEL CGT450 (for boilers with tankless coil)

1 2 3

OPTIONAL
ACTIVATION

Connect “BURNER” terminal on the
CycleGard control to the orange
burner wire (120VAC) located
under the oil burner transformer.

See opposite page for schematic
wiring diagram and additional
SmartCycle description.

Connect input voltage (120 VAC, 60 HZ) to ter­minals 1 and 2.

OPTIONAL ACTIVATION

4 5 6

Connect “LOW LIMIT” terminals on CycleGard
control to the terminals on the tankless aquas­tat.

Connect terminal 2 to burner circuit neutral.
Connect terminal P2 to burner Circuit in series
with other limit controls. Consult boiler manu­facturer instructions for proper terminal connec­tions. Control should be wired in series with and
before other limit controls.

Connect”THERMOSTAT” terminals on
CycleGard control to T-T terminals on burner
primary control.

Optional water feeder connection. Connect feeder
N to terminal 2. Connect Feeder H to terminal 1.
Connect feeder “FEED” or “W” to terminal A. For
water feeders with 2 leads, connect feeder neutral
to terminal 2 and feeder hot to terminal A.

Note: Use of a solenoid valve or McDonnell &
Miller Model 101A water feeder may cause flood­ing and is not recommended for use with this
low water cut-off.

Connect “BURNER” terminal on the CycleGard
control to the orange burner wire (120VAC)
located under the oil burner transformer. See

opposite page for schematic wiring diagram
and additional SmartCycle description.