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103536-13 - 2/24
MegaSteam
Installation & Service Manual
M. PROBE LWCO (HYDROLEVEL CG450,
OR, MCDONNELL-MILLER PSE801-120)
INSTALLATION.
1. Remove either Hydrolevel CG450 LWCO with
factory attached harness and Hydrolevel probe
#EL1214, or, McDonnell-Miller PSE801-120
with factory attached harness and #153875
probe from Control Carton.
2. Install the probe into the appropriate front
section tapping. See Figure 2-8 “Purpose of
Tappings & Bosses”.
3. Slip LWCO with factory attached harness
over the probe and clamp in place. Note that
CG450 LWCO will be positioned right side up,
with diagnostic LED(s) on the top flange, while
PSE801 LWCO will be positioned upside down,
with diagnostic LED(s) on the bottom flange.
Connect the wire(s) between the probe and
control per manufacturer’s instructions.
4. Pick-up the LWCO harness Molex end and
feed it into the enclosure, thru external
electrical enclosure top flange front left 7/8
in. hole; then, snap-in harness BX connector
into the hole, and, plug-in Molex connector
into dedicated LWCO receptacle inside the
enclosure (middle left off transformer/relay).
See “ Control Plug-In Diagram” label attached
to inside of the enclosure cover for details
.
N. PRESSURE GAUGE AND GAUGE GLASS
INSTALLATION.
1. Remove the 6 in. water gauge glass set from
Part Carton.
2. Install the gauge glass using the two ½ in. NPT
tappings to the right of the probe LWCO. See
Figure 2-8 “Purpose of Tappings & Bosses”.
3. Thread the pressure gauge into 1/4 in. NPT
tapping of the front section. See Figure 2-8
“Purpose of Tappings & Bosses”. Tighten with
wrench applied to the square shank of the
gauge.
CAUTION
Do not apply pressure to gauge case, as this
may result in inaccurate readings.
O. AQUASTAT CONTROLLER INSTALLATION
(BOILERS WITH TANKLESS HEATER ONLY).
1. On boilers with tankless heater, install the
L4006A aquastat controller well (found in Part
Carton) into ½ in. NPT tapping in tankless
heater plate.
2. Remove the L4006A aquastat controller with
factory attached harness from Control Carton.
3. Slip the bulb of the aquastat controller into the
well and secure the controller in place with the
set screw.
WARNING
Aquastat bulb must be fully inserted into the
well.
4. Feed the L4006A aquastat controller harness
end thru external electrical enclosure top
flange middle right bushed hole. See “Control
Plug-In Diagram” label attached to inside of
the enclosure cover for details.
5. See Figures 6-2 and 6-3 (whichever
applicable) for tankless heater aquastat
connection details.
6. Using needle nose pliers form hook on
harness each stripped end and wrap hooks
around screws under terminals "R" and "G" of
the R8285C Transformer-Relay; then, tighten
screws securely.
P. SAFETY VALVE AND DRAIN VALVE
INSTALLATION.
1. Remove safety valve and related piping (3/4 in.
NPT x 3 in. lg. black nipple and 3/4 in. NPT 90
˚
black elbow) from Parts Carton.
2. Thread 3/4 in. x 3 in. lg. black nipple into rear
section safety valve tapping, and install 3/4 in.
NPT 90
˚
black elbow facing upward.
3. Thread safety valve into the 3/4 in. NPT 90
˚
black elbow. Pipe the safety valve discharges
as shown in Figure 3-1 "Recommended Boiler
Piping for Gravity Return Steam Boiler" shown
in Section 3 of this manual. Installation of the
safety valve must be consistent with ANSI/
ASME Boiler and Pressure Vessel Code,
Section IV.
WARNING
Safety valve discharge piping must be piped
near floor to eliminate potential of severe burns.
Do not pipe in any area where freezing could
occur. Do not install any shut-off valves, plugs
or caps.
NOTICE:
Lower rear section Tapping "H" is used
for standard condensate return on steam boilers.
4. Remove 1-1/2 in. NPT x 5 in. lg. black nipple,
1-1/2 in. x 1-1/2 in. x ¾ in. NPT black tee and
drain valve from Part Carton.
2
Unit-Pak Boiler Assembly
(continued)
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