F. CONTROLS
This boiler is equipped with a water temperature limit
control which includes a low water cutoff function and
also a reset feature as described below.
1. Water Boiler Controls:
Install the limit / operating control, pressure-
temperature gauge and safety relief valve. See Figure
7.1 (Section 7) for proper location. For installations
subject to UL726, a second operating control that
senses water temperature is also required (not
provided). Use an L4080B or equivalent. Install in
the supply piping near the boiler.
2. Steam Boiler Controls:
a. Steam Boiler with Float Low Water Cut-Off:
Install pressure limit control, pressure gauge, gauge
glass trim and safety valve. See Figure 3.10, Figure
3.11, and Figure 7.1 (Section 7). See also control
manufacturer’s instruction sheet shipped with the
control.
b. Steam boilers with Probe Low Water Cut-Off:
Probe models use a longer gauge glass than float
models. The following components are packed in the
Probe Carton (90759):
·
Hydrolevel CG450 LWCO
·
Gauge glass 22-212-10
·
3/4”x 3” nipple
·
3/4” x 3/4” x 1/4” tee
·
(2) 1/2” couplings
Use these components along with the gauge glass
handles and other components from the Steam Trim
Carton and install fittings and controls per Figure
3.12.
The shorter gauge glass located in the Steam Trim
Carton is not for use with the probe application.
c. Boiler Water Feeders (where used) - See Section 1 -
Preinstallation.
15
PIPING & CONTROLS
In accordance with Section 325
(f) (3) of the Energy Policy and
Conservation Act, this boiler
is equipped with a feature that
saves energy by reducing the
boiler water temperature as
the heating load decreases.
This feature is equipped with
an override which is provided
primarily to permit the use of
an external energy management
system that serves the same
function.
THIS OVERRIDE MUST NOT
BE USED UNLESS AT LEAST
ONE OF THE FOLLOWING
CONDITIONS IS TRUE:
• An external energy
management system is
installed that reduces the
boiler water temperature as
the heating load decreases.
• This boiler is not used for
any space heating
• This boiler is part of a modular
or multiple boiler system
having a total input of 300,000
BTU/hr or greater.
• This boiler is equipped with
a tankless coil.
IMPORTANT
NOTICE
Figure 3.10: Steam Boiler with Float Low
Water Cut-Off
Failure to maintain boiler water quality could result in
a failed heat exchanger.
CAUTION
Pipe the discharge of the safety
valve or relief valve to prevent injury in the event of
pressure relief. Pipe the discharge to a drain. Provide
piping that is the same size as the relief valve.
CAUTION
Use only the Hydrolevel CG450 as
a primary probe low water. The CG450 includes a
cycle timer to sense water level under foaming or
surging conditions. Failure to use this model could
result in a failed heat exchanger.
CAUTION
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