Start-Up; Information For Initial Start-Up; Check, Test & Start Procedure; Motorized Isolation Valve & Relay - Daikin VHF Installation And Maintenance Manual

Information for Initial Start-up

CAUTION
Units must be checked for water leaks upon initial
water system start-up. Water leaks may be a result of
mishandling or damage during shipping. Failure by the
installing contractor to check for leaks upon start-up of the
water system could result in property damage.
Check, Test & Start Procedure
NOTICE
Complete the "Water Source Heat Pump Equipment Check,
Test and Start Form" on page 56.
1 . Open all valves to full open position and turn on power to
the conditioner.
2 . Set thermostat for "Fan Only" operation by selecting "Off" at
the system switch and "On" at the fan switch. If "Auto" fan
operation is selected, the fan will cycle with the compressor.
Check for proper air delivery.
3 . Set thermostat to "Cool." If the thermostat is an automatic
changeover type, simply set the cooling temperature to the
coolest position. On manual changeover types additionally
select "Cool" at the system switch.
Again, many conditioners have time delays which protect
the compressor(s) against short cycling. After a few minutes
of operation, check the discharge grilles for cool air delivery.
Measure the temperature difference between entering
and leaving water. It should be approximately 1½ times
greater than the heating mode temperature difference.
For example, if the cooling temperature difference is 15°F
(8°C), the heating temperature difference should have been
10°F (5°C).
Without automatic flow control valves, target a cooling
temperature difference of 10°F to 14°F (5°C to 8°C). Adjust
the combination shutoff/balancing valve in the return line to
a water flow rate which will result in the 10˚F to 14°F (5°C
to 8°C) difference.
4 . Set thermostat to "Heat." If the thermostat is the automatic
changeover type, set system switch to the "Auto" position
and depress the heat setting to the warmest selection.
Some conditioners have built-in time delays which prevent
the compressor from immediately starting. With most
control schemes, the fan will start immediately. After a
few minutes of compressor operation, check for warm air
delivery at discharge grille. If this is a "cold building" start-
up, leave unit running until return air to the unit is at least
65°F (18°C).
Measure the temperature difference between entering and
leaving air and entering and leaving water. With entering
water of 60°F to 80°F (16°C to 27°C), leaving water
should be 6°F to 12°F (3.3°C to 6.6°C) cooler, and the air
temperature rise through the machine should not exceed
35°F (19°C). If the air temperature exceeds 35°F (19°C),
then the water flow rate is inadequate.
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5 . Check the elevation and cleanliness of the condensate line.
If the air is too dry for sufficient dehumidification, slowly
pour enough water into the condensate pan to ensure
proper drainage.
6 . If the conditioner does not operate, check the following
points:
a . Is supply voltage to the machine compatible?
b . Is thermostat type appropriate?
c . Is thermostat wiring correct?
7 . If the conditioner operates but stops after a brief period:
a . Is there proper airflow? Check for dirty filter, incorrect
fan rotation (3-phase fan motors only), or incorrect
ductwork.
b . Is there proper water flow rate within temperature
limits? Check water balancing; back flush unit if dirt-
clogged.
8 . Check for vibrating refrigerant piping, fan wheels, etc.
9 . Do not lubricate the fan motor during the first year of
operation as it is pre lubricated at the factory.
10 . Field supplied relays installed on the input terminals W1,
W2, W3, W4, Humidistat, Y1, Y2 and G may introduce
electrical noise. Never install relay coils in series with the
inputs.
Motorized Isolation Valve & Relay
The motorized valve kit may be ordered as a factory-installed
options.
Wired as shown in Figure
a call for compressor operation. Valves for unit sizes 009 to
018 are 1/2".
Using a Normally Closed (N/C), power open valve, wire as
illustrated in Figure 57.
Figure 57: Normally closed, power open motorized valve &
relay wiring detail
Note: Connectors on valve must be cut off and stripped back
and the wires twisted to make connections to the IV/PR
Terminals
54
s
57, the motorized valve will open on
Vertical Stack WSHP • IM 986-11
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