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12/06/2012 46
GI202
WARNING
IF THE TTHERM GEO HEAT PUMP IS IN A HARD LOCKOUT WITH THE EARTH LOOP FLOW/
SOURCE WATER LED ON SOLID, DO NOT RESET THE POWER TO THIS HEAT PUMP UNTIL
EARTH LOOP FLOW HAS BE ESTABLISHED. IF THE COMPRESSOR IS OPERATED IN
HEATING MODE WITHOUT WATER, FLOW THE EARTH LOOP HEAT EXCHANGER COULD
FREEZE RUPTURE.
FREEZE RUPTURE IS NOT COVERED UNDER WARRANTY.
Troubleshooting the Relay board
The relay board has 4 LED’s which display which relay is closed.
Yellow – is on when open loop water solenoid is energized.
Green – is on when the source loop pump is running.
Red – is on when the desuperheater pump relay has SWH red wire at L2 voltage.
Blue – is on when the 2
nd
source loop pump is running.
The relay board has 2 – 10 amp fuses providing power for source loop, hydronic, and the desuperheater pumps.
These fuses are 10 Amp type GSF.
Checking the high voltage input terminals
The high voltage enters the relay board on the upper left side, terminals W1 & W2.
This high voltage comes from the source side of the contactor – L1 is connected to W1 and L2 is
connected to W2.
WARNING
DISCONNECT ALL ELECTRICAL POWER BEFORE ELECTRICALLY CONNECTING OR
SERVICING THE UNIT. FAILURE TO DISCONNECT THE ELECTRICAL POWER BEFORE
WORKING ON THIS PRODUCT CAN CREATE A HAZARD LEADING TO PERSONAL INJURY
OR DEATH.
Checking the high voltage output terminals
The high voltage leaves the relay board in 2 locations.
1.
Terminal Block (TB1) is located in the upper right side of the relay board.
See the decal located to the right of the TB1 to determine wiring.
High voltage should be present at the respective terminals when the corresponding LED is on
Load pump terminals will be hot at the same time as source pump terminals.
Tip – if source voltage is present on the board one of the LEDs is on and high voltage is not
present at the corresponding terminals the switching relay is bad and the board will need to be
replaced.
2.
One of the desuperheater terminals (SWH) is located between the fuses and the other SHW terminal
is below the fuses. These terminals carry
High Voltage
. To determine if the desuperheater pump
has power measure across these two terminals. If a desuperheater pump needs to be disabled be sure
the high voltage to the TTHERM GEO heat pump is disabled. Remove the SHW wire from between
the fuses and place it on the parking tab (P) above the relays.
The relay board has one low voltage output for the 24 volt AC water solenoid. The 24VAC “common” wire is
gray and is connected to terminal T7 on the right side of the relay board. The 24VAC “hot” wire is
brown/yellow and is connected to terminal T4.
Tip – if the yellow LED #4 is on and the low voltage is not present at the water solenoid
terminals, the switching relay is bad and the board will need to be replaced.
Summary of Contents for TVA series
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