Maximum Overcurrent Protection (Mop); Electrical Connections-Supply Voltage; Fresh Air Openings; Awst-Factory Installed Txv Models - Daikin AWST18SU14 AA Series Installation Instructions Manual

Maximum Allowable Length in Feet
to Limit Voltage Drop to 2%*
Minimum Circuit Ampacity (MCA)
Wire Size (AWG)
10 15
14 75 50
12 118 79
10 188 125
8 301 201
6 471 314
*Based on NEC 1996

6.2 Maximum Overcurrent Protection (MOP)

Every installation must include an NEC (USA) or CEC
(Canada) approved overcurrent protection device. Also,
check with local or state codes for any special regional
requirements.
Protection can be in the form of fusing or HACR style
circuit breakers. The Series and Rating Plate can be used
as a guide for selecting the MAXIMUM overcurrent
device.
NOTE: Fuses or circuit breakers are to be sized larger
than the equipment MCA but not to exceed the MOP.
IMPORTANT NOTE: Torch heat required to braze tubes of
various sizes is proportional to the size of the tube. Tubes
of smaller size require less heat to bring the tube to
brazing temperature before adding brazing alloy. Applying
too much heat to any tube can melt the tube. Service
personnel must use the appropriate heat level for the size
of the tube being brazed.
NOTE: The use of a heat shield when brazing is
recommended to avoid burning the serial plate or the finish
on the unit. Heat trap or wet rags should be used to protect
heat sensitive components such as service valves and TXV
valves.
6.3 Electrical Connections – Supply Voltage
USE COPPER CONDUCTORS ONLY.
A knockout is provided on the air handler top panel or side
to allow for the entry of the supply voltage conductors. If
the knockouts on the cabinet sides are used for electrical
conduit, an adapter ring must be used in order to meet
UL1995 safety requirements. An NEC or CEC approved
strain relief is to be used at this entry point. The wire is to
be sized in accordance with the "Electrical Wire and MOP"
section of this manual. Some areas require the supply wire
to be enclosed in conduit. Consult your local codes.
Achieving Less Air Leakage:
Ensure all the gaskets remain intact on surfaces as
shipped with the unit. When these requirements are
satisfied, the unit achieves the following airflow leakage
when tested in accordance with ASHRAE Standard 193:
- Cabinet air leakage less than 2% at 1.0 inch H2O
- Cabinet air leakage less than 1.4% at 0.5 inch H2O
20 25 30 35
37 NR NR NR
59 47 NR NR
95 75 63 54
150 120 100 86
235 188 157 134
Table 2

6.4 Fresh Air Openings

All AWST models include 4" fresh air knockouts
on both sides of the cabinet. To utilize, simply remove the
appropriate knockout and connect fresh air inlet venting
directly to cabinet. Ensure the unit mounting system does
40 45
not block the fresh air inlet holes.
NR NR
NOTE: The installing contractor must take into account any
NR NR
lost capacity due to the the fresh air openings when sizing
NR NR
the equipment.
75 68
118 110

7 AWST-Factory Installed TXV Models

AWST air handlers come equipped with a factory installed
fully adjustable TXV for air handler installation follow the
below installation procedure.

7.1 Tubing Size

For the correct tubing size, follow the specification for the
condenser/heat pump.
7.2 Tubing Connections
An adjustable TXV with bulb is installed on the vapor tube
from the factory.
Note: The TXV must be adjustable to meet the outdoor
unit's target superheat value. During the superheat
adjustment on the TXV, the torque applied on the nut
cannot exceed 25 in-lbs. Refer to the EXPANSION
VALVE TROUBLESHOOTING section of this manual for
assistance with the adjustable TXV.
For air handler installation, follow the installation procedure
below.
1. Remove the front access panel.
2. Remove access valve fitting cap and depress the valve
system to release pressure. No pressure indicates
possible leak.
3. Replace the fitting cap.
4. Remove the copper cap on both the liquid line and
suction line. The copper caps caused by the refrigerant
lines. DO NOT USE ANY FORM OF CUTTING
METHOD. CUTTING THE CAPS MAY RESULT IN THE
GENERATION OF COPPER SHAVINGS OR COPPER
DUST.
5. Insert liquid line into liquid tube expansion and
slide grommet about 18" away from braze joint.
6. Braze suction line set into suction tube expansion and
slide insulation about 18" away from braze joint.
7. Braze joints and quench all brazed joints with water or
wet rag upon completion of brazing.
4