Maritime Geothermal TF-45, Инструкция по установке и обслуживанию

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Page 10 001223MAN-05 1-Jul-2017
TABLE 7 - Control Board Fault Codes
Fault LED Flashes
High Pressure 1
Low Pressure 2
Condensate Overflow 4
Brownout 5
Safety Controls
The heat pump has two built in safety controls which are
designed to protect the unit from situations which could damage
it should the operation of the refrigeration circuit fall outside the
allowable operating range.
A. Low Pressure Control
The low pressure control monitors the compressor suction
pressure and will shut the compressor down if the refrigerant
evaporating pressure becomes too low, risking the danger of
freezing conditions in the evaporator.
There are (3) main reasons why this control would activate
in response to the operating conditions of the unit while operat-
ing in heating mode:
1. Low or no outdoor loop flow.
2. Low outdoor loop entering liquid temperature.
3. Dirty or fouled outdoor loop heat exchanger.
B. High Pressure Control
The high pressure safety control monitors the compressor
discharge pressure and will shut the compressor down if the
condensing pressure becomes too high.
There are (3) main reasons why this control would activate
in response to the operating conditions of the unit while operat-
ing in heating mode:
1. Low or no airflow.
2. High return air temperature.
3. Dirty air coil due to poor filter maintenance.
The unit contains a control board that monitors the safety
controls and operates the compressor accordingly. The low
pressure control and high pressure controls are connected to
the control board as shown on the wiring diagram later in this
manual.
The compressor will not be allowed to start if a ‘fault’ con-
dition exists. A ‘fault’ occurs if either one of the pressure con-
trols exhibits an open circuit. In addition, the board monitors a
condensate overflow sensor, located in the drip tray, and the
voltage of the 24vac transformer. A fault will occur if a conden-
sate overflow is detected, or a low voltage condition (electricity
grid brownout) is detected.
The control board has an on-board LED and an ALR pin
with a 24VAC output, which is routed to the L terminal of the
thermostat terminal strip. An external indicator or relay can be
connected across L and C on the terminal strip if external signal-
ing is desired. Should a fault condition occur, the LED will flash
the code of the fault condition. The codes are shown in TABLE
5. The control board will lock out the compressor for five
minutes when a fault occurs. The control board will then restart
the compressor if the fault has been cleared. Should a second
fault condition occur within a 60 minute period the control board
will go into permanent lockout mode and energize the ALR pin.
The LED will flash the fault code until the control board is reset
by powering down the unit.
The board has a TEST jumper, described on the Trouble-
shooting Guide page later in this manual.
WARNING: If the control board enters perma-
nent lockout mode there is a serious problem
with the system and it must be rectified if the
unit is to maintain good service.
WARNING: REPEATED RESETS OF A LOW
PRESSURE LOCKOUT COULD CAUSE THE
HEAT EXCHANGER TO FREEZE AND RUP-
TURE, DESTROYING THE HEAT PUMP AND
VOIDING THE WARRANTY.
Domestic Hot Water
(Desuperheater) Connections
The port connections for the DHW circuit are 1/2” brass FPT
fittings. They are marked as DHW IN and DHW OUT.
A typical piping diagram for a pre-heat tank configuration
can be found in drawing 000970PDG at the end of this section.
Be sure to note the position of the check valve and the direction
of water flow. Other configurations are possible, and there may
be multiple units tied together in larger buildings.
Ensure the tank is filled with water and under pressure
before activating the built-in DHW circulator as described below.
First, slightly loosen the boiler drain on the DHW Out pipe to
allow air to escape from the system. This step will make certain
that the domestic hot water circulator in the unit is flooded with
water when it is started.
Activate the built-in DHW circulator by connecting the
brown wire with the blue insulated terminal to L1 of the com-
pressor contactor. Ensure the power is off when connecting the
wire.
The DHW loop may have to be purged of air several times
before good circulation is obtained. A temperature difference
between the DHW In and DHW Out can be felt by hand when
the circulator pump is operating properly.
For the pre-heat tank setup, the final tank should be set to
140°F(60°C), which is required by most codes. The pre-heat
tank does not require electric elements. This setup takes full
advantage of the desuperheater as it is the sole heat provider to
the pre-heat tank. The desuperheater remains active during the
compressor runtime until the pre-heat tank has been completely
heated by the desuperheater alone. This setup is more energy
efficient than a single tank setup, and eliminates the possibility
of reverse heating of the refrigerant gas in cooling mode.
WARNING: USE ONLY COPPER LINES TO
CONNECT THE DESUPERHEATER. TEM-
PERATURES COULD REACH 200F SHOULD
THE DHW CUTOUT SWITCH FAIL, POTEN-
TIALLY MELTING & RUPTURING PLASTIC
PIPING.
CAUTION: the domestic hot water pump is
water lubricated; damage will occur to the
pump if it is run dry for even a short period
of time.
CAUTION: If two (2) shut-off valves are
located on the domestic hot water ines as
shown in the diagram, a pressure relief valve
must be installed to prevent possible dam-
age to the domestic hot water circulator
pump should both valves be closed.