Maritime Geothermal nordic dx-45, Руководство по установке

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Maritime Geothermal Ltd. 12-Feb-00
The NORDIC® heat pump has two built in safety controls
which are designed to protect the unit from situations which
could damage it.
1. Low pressure control
The low pressure control is designed to shut the unit down
if the refrigerant evaporating pressure drops below 20 psig.
Some possible causes for a trip out on low pressure are:
1.Ruptured or broken groundloop coil
2.Low refrigerant charge.
2. High pressure control
The second safety control is a high pressure safety limit
which monitors compressor discharge pressure. This device
will not normally trip unless there is an interruption in air
flow. Such a situation could occur if the blower motor or fan
belt failed or if the heat pump had an extremely dirty air filter.
If either of these controls trips it will activate a
lock-out relay which prevents the unit from restarting until
power to the control circuit is broken (by turning the thermo-
stat to the OFF position and then back on again) or the electri-
cal supply to the unit is broken by opening the heat pump
breaker and then closing it again. If one of these controls trips
there is a serious problem with the system and it must be rec-
tified if the unit is to maintain good service.
Electrical
The NORDIC® unit is supplied with an opening for 3/4"
conduit nipple on the right side of the unit. An additional 1/2"
knock-out is also supplied to accommodate accessories which
may be attached to the heat pump's relays (such as electronic
air filters humidifiers etc.). Above the accessory knock-out is
another 3/8" hole for the thermostat wire. A wiring diagram is
located on the electrical box cover for quick reference and
although the connections to be made are quite simple, Mari-
time Geothermal Ltd. recommends that a properly qualified
electrician be retained to make the connections and wire the
thermostat.
The NORDIC® unit comes supplied with a thermo-
stat and connections are clearly marked on the control box.
Ductwork
Ductwork layout for a heat pump will differ from normal
design in the number of leads and size of main trunks re-
quired. Air temperature leaving the heat pump is normally 95°
to 105° F., much cooler than that of a conventional warm air
furnace. To compensate for this, larger volumes of lower tem-
perature air must be moved and consequently duct sizing must
be able to accommodate the greater air flow without creating
a higher static pressure or high velocity at the floor diffusers.
Maritime Geothermal Ltd. recommends that the static pres-
sure be kept below .2 inches of water total. Return ducts
should ideally be placed in every room and be sized 50% lar-
ger than corresponding supplies. In some instances the num-
ber of floor diffusers will actually double when compared to
the number that would normally be used for a warm air
oil-fired furnace.
Starting the Heat Pump
BEFORE starting the heat pump the following areas
should be rechecked to assure proper operation.
1.
Check all high voltage field wiring and electrical connec-
tions inside the control box for good connection.
2. Check all low voltage thermostat to make sure they are
connected properly. Place thermostat HEAT-OFF-COOL
switch in the OFF position.
3. Turn on the main power switch. Allow the power to re-
main ON without starting the unit for a period of 4 hours.
Refrigerant migrates to the compressor oil when the com-
pressor is unheated. A crankcase heater is standard equip-
ment on your heat pump and it will warm the compressor,
dispelling the liquid refrigerant.
4. Turn on the water supply to the hot water generator and
check all plumbing for leaks.
5. Check the hot water tank to be sure it is filled with water
before energizing the circuit. Slightly open the union on
the hot water discharge pipe to make sure that all air is
out of the system and the circulator pump is flooded with
water.
6. Make sure the air filter is clean and in place.
7. Vacuum out any dust and debris that may have collected
in the unit during installation. Check the condensate drain
to be sure that it is free of obstruction.
8. Make sure the unit is sitting level so that condensate wa-
ter will not overflow the catch pan.
9. Make sure the proper time-delay fuse has been installed
in the fuse box.
10. Have the following tools on hand and know how to use
them.
•
A refrigeration gauge set.
•
An electronic or other accurate thermometer.
•
An amprobe.
1. Connect your refrigeration gauge set.
2. After the 4 hour warm-up period place the thermostat
function switch in the HEAT position, turn up the ther-
mostat. The compressor, blower and hot water circulator
will start.
3. Observe the readings on the high and low pressure gauge
set. When the home reaches a temperature of 65° to 70 °
F. the suction pressure (blue gauge) should be approxi-
mately 54 to 58 psig. while the head or discharge pres-
sure (red gauge) should be in the area of 225 to 275 psig.
Record this information on the warranty test card.
4. Record the return air temperature by drilling a small hole
in the return air plenum approximately 2 ft. from the filter
rack and inserting the thermometer's sensing device.
5. Similarly record the discharge air temp. There should be
a rise across the air exchanger of from 25° to 35° °F.
6. At the electrical disconnect switch place the amprobe