BT Series Electric Boilers – Installation, Operating and Maintenance Instructions
7
Startup Instructions
Section 4
4.1 WARNING
WARNING
The following instructions are intended as a guide for qualified persons. Before switching the
power on, fill the system with water and vent air. Check for and repair any leaks in the water
piping.
4.2 STARTUP
a. Fill System
Figure 2 shows the suggested set-up for a make-up water supply using a pressure regulator (not supplied
by manufacturer). Do not apply full line make-up water pressure to the system. Fill the system to
approximately 12 psi (cold water) if the expansion tank is pressurized at 12 psi. The expansion tank
should be sized to provide the system with enough volume for thermal expansion and contraction while
maintaining operating pressures within safe and reasonable limits. There should be no significant
pressure fluctuations in systems having both an effective automatic fill valve and a properly sized
expansion tank or expansion tank arrangement. The standard pressure relief valve supplied with the
boiler is rated at 30 psi, or as required by order, but the maximum working pressure cannot exceed 90 psi
for CSA or A.S.M.E. approved boiler. Once the system is filled with water, all trapped air must be
removed to avoid air locks, which can reduce flow rate and cause thermal shock. Figure 2 also illustrates
the connections to the air purger (not supplied by manufacturer) and expansion tank in the line from the
boiler to the radiation units. Additional air purgers should be installed at high points in the system to
assist in removing air which can accumulate from the water supply line. All high points must be vented.
b. Startup Procedure
Perform the following procedure as a check for proper boiler and system operation:
1. Set the boiler operating temperature to the designed heating water temperature by adjusting the dial
of potentiometer located on the bottom-left of the controller (Figure 3). Use a small screwdriver to
adjust the arrow on the temperature adjustment dial to the water temperature required. (This boiler is
also equipped with a non-adjustable, high-limit temperature device set at 230
°
F as safety limit control.
The high limit temperature device has an automatic reset function.)
2. The stage 1, stage 2, and stage 3 contactors are each connected in series with Anti-Cycle Cubes.
Use a small screwdriver to adjust the arrow on the Cube adjustment dial to the required stage time
delay. The recommended Anti-Cycle Cube settings are two minutes for stage 1, five minutes for
stage 2 and eight minutes for stage 3.
Minimum Settings:
The stage 1 Cube should be set at a
minimum of
one minute.
The stage 2 Cube should always be set a minimum of
two minutes longer
than stage 1
.
The stage 3 Cube should always be set a minimum of
two minutes longer than
stage 2
.
3. Turn up all room thermostats above room temperature.
4. When power is supplied to the controller, the power indicator LED (green) is always on. When the
thermostat calls for heat, the pump will be energized immediately and the pump indicator LED
(yellow) will light up. Next, the three stages are energized along with the stage indicator LEDs
(yellow), one after another, in sequence and based on the time delay which is user-set by the Anti-
Cycle Cubes. Once the boiler water temperature reaches the set point on the temperature adjustment
dial, the controller will regulate the boiler water temperature with three stages. The number of stages
which stay on is based on the heating demand and the set point of the boiler water temperature.
After all room thermostats are satisfied with the heat, the controller de-energizes the three stages one
after another, in sequence, and then switches the pump off.
5. Current may be checked by a qualified electrician at the feeder panel and compared to the values
shown in Table 1.
