CleaverBrooks CB-LE Series - H. HIGH LIMIT PRESSURE CONTROL (STEAM); I. MODULATING TEMPERATURE CONTROL (HOT WATER)

Chapter 6 — Adjustment Procedures
Part No. 750-184 6-9
in” (burner-on) pressure is the cut-out pressure MINUS the
differential. The cut-out pressure should not exceed 90% of the
safety valve setting.
H. HIGH LIMIT PRESSURE CONTROL (STEAM)
Set “cut-out” (burner off) pressure on the main scale using the
adjusting screw. The control will break a circuit when pressure
reaches this point. The setting should be sufficiently above the
operating limit pressure control to avoid shutdowns, and preferably
not exceed 90% of safety valve setting. The control requires
manual resetting after tripping on a pressure increase. To reset,
allow pressure to return to normal and then press the reset button.
I. MODULATING TEMPERATURE CONTROL (HOT
WATER)
Turn the knob on the front of the case until the pointer indicates the
desired setpoint temperature. The desired set point is the center
point of a proportional range. The control has a 3 to 30° differential
and may be adjusted to vary the temperature range within which
modulating action is desired. With the cover off, turn the adjustment
wheel until pointer indicates desired range.
!
Caution
To prevent burner shutdown at other than low-fire setting adjust
modulating temperature control to modulate low fire BEFORE
operating limit temperature control shuts off burner. Failure to
follow these instructions could result in damage to the equipment.
J. OPERATING LIMIT TEMPERATURE CONTROL (HOT
WATER)
Set “cut-out” (burner off) temperature on the scale by inserting a
screwdriver through the cover opening to engage the slotted head
adjusting screw. The “cut-in” (burner on) temperature is the cut-out
temperature MINUS the differential. The differential is adjusted
from 5 to 30° F.
K. HIGH LIMIT TEMPERATURE CONTROL (HOT
WATER)
Set the “cut-out” (burner off) temperature on scale using the
adjusting screw. The control will break the circuit and lock out
on a
rise in water temperature above the setting. The setting should be
sufficiently above the operating limit temperature to avoid
unnecessary shutdowns. On a 30 psig hot water boiler, the setting
is not to exceed 240° F. The control requires manual resetting after
tripping on a temperature increase. To reset, allow the water
temperature to drop below the cut-out setting less differential, and
then press the manual reset button.