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2005 Boreal Geothermal Inc.
www.boreal-geothermal.com
The BCB has another terminal block on the middle left
side which accepts inputs from the high & low refrigerant
pressure controls as well as the loop maximum pressure
switch. These connections are pre-wired at the factory and the
installer need not concern himself with the connections unless
he is replacing the board for some reason.
The connections are marked:
H / H
- To and from the normally closed HIGH
refrigerant
pressure
switch.
L / L
- To and from the normally closed LOW
refrigerant
pressure
switch.
A +5v DC signal is sent out continuously on one side of
each of these controls. If the BCB does not see +5v coming
back it knows the pressure control has opened and takes ac-
tion to shut down the compressor.
S / S
A +5v DC signal is sent out continuously to one side of
this Normally Open pressure switch. The BCB is normally
looking for a 0 voltage on the return lead. If +5v is seen on
the return lead then the BCB knows the switch has closed
because of a limit pressure condition in the ground loop and
will take action to switch loops. There is an LED indicator
light which will light when the loop pressure switch is closed.
This light will go out when the heat pump changes loops and
loop pressure drops back below the reset pressure of this
switch.
Other INPUTS
Initial setup of the BCB requires that the board know,
during the cooling mode, whether it is on a 2, 3, 4, or 5 loop
system. The BCB can then decide which loops to cycle and in
what order. This is accomplished by setting the position of
two shunt style jumpers located between the microprocessor
and the ROM chip. (See diagram A)
Possible settings are:
1. Both jumpers removed - 2 loop system
2. Left jumper only - 3 loop system
3. Right jumper only - 4 loop system
4. Both jumpers installed - 5 loop system
These jumpers are normally set at the factory and would
only be altered by a dealer in the case of an initial setup of a
replacement control board etc.
Outputs
In keeping with the philosophy above of keeping the 24v
ac control power out of the BCB, the outputs of the controller
board are optically coupled to solid state switches so that the
worst malfunction in wiring etc. would produce only minor
damage if at all to the output section of the control board.
There are 12 output connections at the bottom of the BCB
located on (2) two 6-terminal connectors. Terminal designa-
tions are as follows:
(Left to Right) (Left Block)
1. Cooling Loop # 1
2. Cooling Loop # 2
3. Cooling Loop # 3
4. Cooling Loop # 4
5. Cooling Loop # 5
6 . Soaker Hose
(Left to Right) (Right Block)
7.
Electric
Heat
8.
Reversing
Valve
9.
Blower
10.
Compressor
11. "R" “HOT” side of control transformer.
12. "C" “COMMON” side of control transformer.
NOTE: Observe location of "R" and "C" -- they must
not be reversed.
Indicator LED's
There are 14 LED indicator lights on the BCB which
show the status of ON/OFF functions being controlled by the
board. Each of the first 5 outputs (loop solenoids) has a green
LED light to indicate which loops are being operated at any
one time. Terminals 6 through 10 above have a red LED.
Three additional LEDS are located near the center of the
board which are (from left to right):
1. High pressure lockout indicator.
2. Low pressure lockout indicator.
3. Heartbeat - Heartbeat (1 per second) flashes continu-
ously whenever the board is powered up to indicate
normal system operation.
One additional yellow LED located near the upper right
corner of the BCB will light whenever the loop pressure limit
switch closes.
Method of Operation - Heating Mode Checkout
When the thermostat has been connected and the system
powered up, move the selector switch to heat mode and turn
up the thermostat. The compressor will come ON followed by
the BLOWER after a short delay.
The system will remain on until the thermostat is satis-
fied or the MODE switch is changed. During the heating cy-
cle the AUX. HEAT can come on to assist the heat pump in
one of two manners.
1. If the system is ON for more than 30 minutes
(adjustable) the AUX. HEAT will come on to
assist reaching the room set point. (Follows 1st
stage contact.)
2. Second stage contact closes sending a signal to
"W".
Once the thermostat is satisfied the compressor will shut
OFF followed by the blower after a 10 second delay.
(adjustable) If the AUX. HEAT has been on then the delay
will be 60 seconds before the blower shuts off (adjustable).
