Slant/Fin EH - Manual (Page 2)

DESCRIPTION
The Monitron boiler is a low pressure hot water heating electric
boiler. The heating elements are sheathed resistance type. The
heat exchanger is cast-iron. The heat exchanger is constructed,
inspected, and stamped in accordance with Section IV of the
American Society of Mechanical Engineers (ASME) Boiler and
Pressure Vessel Code. In addition, the Monitron Boiler is
equipped with a safety relief valve and an integral dual limit con-
trol, conforming to ASME requirements. The Monitron boiler is
Underwriters' Laboratories, Inc. listed.
MOUNTING
The Monitron is intended for wall mounting, utilizing the wall
brackets attached to the boiler (see Figure 1). Allow sufficient
space for piping and service. The boiler may be installed in an
enclosed space (see Figure 1). The boiler must be INSTALLED
LEVEL.
PIPING
Air Separator and Expansion Tanks
The recommended piping arrangement is shown in Figures 2
through 4. Note that there is a built-in air eliminator in the heat
exchanger (air vent, however, is by others). A 1/8" air vent may
be used. Additional air vents should be installed at points just
upstream from all drops in elevation of the piping system (high
points).
Flow Switch
A FLOW SWITCH MUST BE INSTALLED. It is intended to pre-
vent the burnout of heater elements should the circulator fail, or
should air accumulate in the boiler due to faulty air elimination
(see Table 3 for flow switch size required). FLOW SWITCH
MUST BE INSTALLED IN HORIZONTAL POSITION.
Bypass
The bypass shown must be set so that a sufficient amount of
water can circulate through the boiler when all zone valves are
closed. See Figure 3.
Multi-zone Balancing
Raise all zone thermostat settings and verify that all zone valves
are open (not bypassed). Close all electrical panels. Turn on 10
amp control circuit breaker ONLY. Pump should operate. Note
the pressure reading on the pump discharge. Lower each zone
thermostat setting to close corresponding zone valve. Adjust the
corresponding balancing valve to maintain pump discharge pres-
sure. The pump discharge pressure should remain the same
when all zones are in bypass or when all zones are open or any
combination of opened and closed. See Figure 4.
WIRING
To wire the electric boiler, perform the following procedures:
1. Wall Thermostat Flow Switch and Circulator
• All circuit breakers ahead of and at boiler must be OFF.
Remove the Control Panel (left-hand front) Cover by
removing 5 screws from top, bottom and side flanges.
• The right-hand compartment under the Control Panel
Cover contains a terminal board marked, "TTFF". Wire a
2-wire 24V heating thermostat or the auxiliary end switch
terminals of zone valves (see Figure 5) to "TT" at this
time. The "FF" terminals are for the flow switch. You may
draw the wires between the flow switch and the compart-
ment containing the "TTFF" terminal board but the wires
at the flow switch end may NOT be connected and the
ends should be taped. The flow switch circuit is a low volt-
age circuit (see wiring diagram, Figure 5).
• Wire the circulator and connect wires and conduit through
1/2" K.O. provided on bottom left hand corner, to the ter-
minal board marked, "Circulator". Wire zone valve trans-
former to terminals "A" and "B" of this terminal board (see
Figure 6) if zone valves are used. Use 75°C. minimum
wire, copper or aluminum.
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