Hydrolevel 400 Series - Manual (Page 3)

CYCLEGARD
LOW-WATER
CUT-OFF
CYCLEGARD
LOW-WATER
CUT-OFF
Principle of Operation
Hydrolevel controls are electrically operated. A probe is installed in the boiler shell and connected to the control unit. Water is used as a conductor to
complete a circuit from the probe to the control unit. The control unit provides switching contacts to complete the burner control circuit and to operate an
optional alarm or water feeder.
LOW WATER CONDITION NORMAL OPERATION
P 1
BURNER
POWER
P 2 P 1
BURNER
POWER
P 2
With water present at the probe, the control circuit is complete.
Contact between terminals P1 and P2 completes the burner circuit,
allowing for normal operation of the burner. Whenever the water falls below the probe, a time delay is activated
in the control. After 15 seconds of a low water condition, the control
interrupts the burner circuit and shuts down the boiler. This time
delay feature prevents short cycling of the burner circuit during tem-
porary low water levels common in turbulent steam boiler environ-
ments.
NOTE
For proper low water cut-off operation, the boiler should be cleaned at
initial installation and periodically thereafter. Refer to the boiler manu-
facturer’s instructions for cleaning procedures.
OPERATING TEST PROCEDURE
1. After installation, bring the boiler water to a safe operating level, turn
on power and set the thermostat to call for heat. The amber LED
lamp should be off. The boiler will fire after a 30 second delay.
2. Slowly lower the boiler water to a point below the probe. The amber
LED lamp on the control will light. The lamp may begin to flicker
with the bouncing water level. Stop draining the boiler when the
lamp glows steadily. NOTE: The water should not be lowered
beyond a visible point in the gauge glass.
3. The boiler will shut down within 15 seconds.
IF BURNER DOES NOT SHUT DOWN IN LOW WATER
1. Check terminal block wiring to insure that all connections are
correct.
2. Check the probe installation to insure that there is 1/4" clearance
from any surface within the boiler or pipe. (Refer to Step 3 on page
1 of this instruction sheet.
3. Clean the boiler in accordance to the manufacturer’s instructions.
Machining oils, grease, rust and other contaminants in the boiler
water can cause foaming or surging and make a low water condition
difficult to detect during burner operation.
IF THE AMBER LED LAMP IS ON
The amber LED lamp indicates that the water is below the probe. If the
gauge glass shows that the water is at the correct operating level and
the amber LED is lit check the following:
1. Check for plugged gauge glass.
2. Make sure probe lead wire is properly secured to the terminal.
3. Check for proper ground between probe and boiler shell. Excessive
use of Teflon tape or sealing compound may isolate the probe from
the boiler shell.
4. Remove probe and examine for oily residue. Clean probe with steel
wool and skim boiler.
To ensure optimum performance remove and inspect probe annually. Clean any sediment or scale from the probe using a scouring pad or steel
wool. Re-install the probe and perform the Operating Test Procedure described above.
Operating Instructions
Maintenance