Daikin DZ17VSA481AA - System Connection and Start-Up Procedures; Connect Heat Pump to System; Liquid Valve First Opening Caution; System Start-Up Test Reference

1818
Step 2. connect heat pump to SyStem
CAUTION
open the lIquId ValVe fIrSt!
If the SuctIon SerVIce ValVe IS opened fIrSt, oIl from the com-
preSSor may Be drawn Into the Indoor unIt, reStrIctIng refrIger-
ant flow and affectIng operatIon of the SyStem.
CAUTION
poSSIBle refrIgerant leak!
to aVoId a poSSIBle refrIgerant leak, open the SerVIce ValVeS
untIl the top of the Stem IS 1/8” from the retaIner.
CAUTION
enSure ValVeS are open and addItIonal charge IS added per
chart Before applyIng power.
Charge additional refrigerant calculated by STEP formula &
table from liquid service valve. (NOT from suction side.)
When opening service valves, open each valve only until the
top of the stem is 1/8” from the valve. To avoid loss of refriger-
ant, DO NOT apply pressure to the retainer. When opening
valves without a retainer, remove service valve cap and insert
a hex wrench into the valve stem and back out the stem by
turning the hex wrench counterclockwise.
After the refrigerant charge has bled into the system, open
the liquid service valve. The service valve cap is the second-
ary seal for the valves and must be properly tightened to
prevent leaks. Make sure cap is clean and apply refrigerant
oil to threads and sealing surface on inside of cap. Tighten
cap nger-tight and then tighten additional 1/6 of a turn to
properly seat the sealing surfaces.
Break vacuum by fully opening liquid and suction base valve.
NOTE: 1.5 - 3.0 ton have front seating valves. 3.5 - 5.0 ton
have front / back seating valve. Refer detail function on page
11. It is not necessary to force the stem tightly against the
rolled lip.
equIValent length calculatIon
NOTE: The following table lists the equivalent length gained
from adding bends to the suction line. Properly size the suc-
tion line to minimize capacity loss.
Type of Elbow Fitting
Inside Diameter
3/4 7/8 1 1/8
90° short radius 1.7 2 2.3
90° long radius 1.5 1.7 1.6
45° radius 0.7 0.8 1
unit: inch
Step 3. SyStem Start-up teSt
For a detailed procedure, please visit the Daikin One+ website
at https://www.daikinone.com
addItIonal charge adjuStIng procedure
Step 4. adjuSt refrIgerant leVel
Using service equipment, add or recover refrigerant according
to the refrigerant calculation. Allow system to stabilize for 20
minutes after adjusting charge level.
Step 5. meaSure SuBcoolIng to VerIfy
proper charge
If want to adjust charging by checking “Subcooling”, please
follow below.
NOTE: Charging equipment must use dedicated PVE oil
gauges and hoses.
1. Purge gauge lines.
2. Connect service gauge manifold to liquid base valve
service ports.
3. Convert the liquid pressure to temperature using a
temperature/pressure chart.
4. Temporarily install a thermometer on the liquid line at
the liquid line service valve.
Ensure the thermometer makes adequate contact and
is insulated for best possible readings.
5. Subtract the liquid line temperature from the converted
liquid pressure to determine subcooling.
6. Before starting the subcooling adjustment, make sure
the outdoor ambient temperature is in a below range
and the unit is operating at 100% capacity.
If the unit is operating at 100% capacity which is ready
for charge by subcooling, seven segments will light up
as “cha”.
But, if the unit is not operating at 100% capacity which
is not ready for charging, seven segments will ush
as “cha”.
7. If the system subcooling is not within the range
as shown in the following table, adjust subcooling
according to the following procedure.
a. If subcooling is low, add charge to adjust the
subcooling as specied in the following table.
b. If subcooling is high, remove charge to lower the
subcooling to below charging table value.