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6 - START-UP
Use the procedure outlined below to initiate proper unit start-up.
NOTE: This equipment is designed for indoor installation only.
WARNING: When the disconnect switch is closed, high
voltage is present in some areas of the electrical panel. Exercise
caution when working with the energised equipment.
1.
Adjust all valves to the full open position and turn on the
line power to all heat pump units.
2.
Operate each unit in the cooling mode first. Room tempe-
rature should be in the normal range (i.e., approximately
10 to 27
°
C dry bulb). Loop water temperature entering the
heat pumps should be at least 4
°
C but not in excess of
43
°
C. Refer to Table 4 for more specific information on
the operating parameters of units.
NOTE: Three factors determine the operating limits of a unit:
(1) return-air temperature, (2) water temperature and (3)
ambient temperature. Whenever any one of these factors is at
a minimum or maximum level, the other two factors must be
at normal levels to ensure proper unit operation. Flow rates
must be at nominal levels.
6.1 - Unit start-up/cooling
1.
Turn the unit thermostat to the cooling position and turn
the fan speed switch to “HI.” If the unit has an optional
MCO thermostat, set the selector switch to cool. Both the
fan and compressor should run.
2.
Check for cool air delivery at unit grille 15 minutes after
the unit has begun operating. List the identification
number of any machines that do not function at this time.
3.
Check the elevation and cleanliness of the condensate lines;
any dripping could be a sign of a blocked line.
4.
Select low fan speed. Air flow should decrease and com-
pressor should operate.
5.
Slowly turn thermostat toward warmer position. Both fan
and compressor should shut off when thermostat set point
equals room temperature. Room temperature must be
below 32
°
C for unit to shut off.
6.
Operate each heat pump in the heating cycle immediately after
checking cooling cycle operation. A time delay will prevent
the compressor from re-starting for approximately 5 minutes.
6.2 - Operating limits
Environment - This equipment is designed for indoor installa-
tion ONLY.
Power supply - A voltage variation of
±
10% of nameplate
utilisation voltage is acceptable.
50KQE starting conditions - The 50KQE units will start and
operate at an ambient temperature of 10
°
C with entering air
temperature at 10
°
C, entering water at 16
°
C, and with both air
and water at nominal flow rates.
NOTE: These operating limits are not normal or continuous
operating conditions. It is assumed that such a start-up is for
the purpose of bringing the building space up to occupancy
temperature.
6.3 - Unit start-up/heating
1.
Adjust the unit thermostat to the warmest setting and turn
the fan speed switch to “HI.” If the unit has an optional
MCO thermostat, set the selector switch to heat. The
blower should start immediately and after the time delay is
complete, the compressor will start.
2.
Once the unit has begun to run, check for warm air delivery
at the unit grille. Again, the installing contractor must list
the serial number of any machine that does not function.
3.
Log the unit operating conditions at initial start-up for
each unit to establish a permanent operating record.
4.
Select low fan speed. Airflow should decrease and com-
pressor should continue to operate.
5.
Slowly turn thermostat toward cooler position. Both fan
and compressor should shut off when thermostat set point
equals room temperature. Room temperature must be
above 19
°
C for unit to shut off.
6.4 - Flow regulation
Flow regulation can be accomplished by two methods. Most
water control valves have a flow adjustment built into the valve.
By measuring the pressure drop through the unit heat exchanger,
the flow rate can be determined (see Table 8). Adjust the water
control valve until the flow of 0.027 to 0.036 l/s per kW cooling is
achieved. Since the pressure constantly varies, two pressure
gauges may be needed in some applications.
An alternative method is to install a flow control device. These
devices are typically an orifice of plastic material designed to
allow a specified flow rate that are mounted on the outlet of the
water control valve. Occasionally these valves produce a velocity
noise that can be reduced by applying some back pressure. To
accomplish this, slightly close the leaving isolation valve of the
well water set-up.
CAUTION: DO NOT use “Stop Leak” or any similar chemical
agent in this system. Addition of these chemicals to the loop
water will foul the system and inhibit unit operation.
Table 8 - Coaxial water pressure drop
50KQE
Flow
Pressure drop, kPa
l/s
0
°
C
10
°
C
20
°
C
30
°
C
007
0.063
12.1
7.8
6.5
5.7
0.088
16.8
12.6
11.5
10.5
0.114
23.2
18.5
17.9
16.4
009
0.069
4.5
3.3
2.7
2.7
0.101
6.1
5.4
5.1
4.8
0.133
9.7
8.4
7.4
6.8
012
0.076
5.1
3.9
3.3
3.0
0.107
7.2
5.7
5.7
5.4
0.145
11.5
10.2
9.1
8.4
015
0.101
10.8
7.8
7.8
6.9
0.145
16.1
12.9
12.9
12.6
0.196
26.8
23.0
34.2
20.8
019
0.107
11.1
8.7
8.0
7.8
0.158
17.9
15.5
15.0
14.1
0.208
34.4
27.5
25.1
24.0