Carrier 48AJ/AK/AMD020, Installation Instructions Manual

Page: 18 / 48

18
Step 5 — Trap Condensate Drain —
See Fig. 5-10
for drain location. Condensate drain is open to atmosphere and
must be trapped. Install a trapped drain at the drain location.
One 1-in. FPT coupling is provided inside the unit evaporator
section for condensate drain connection. A trap at least 4-in.
deep must be used. See Fig. 14. Trap must be installed to pre-
vent freeze-up.
Condensate pans are sloped so that water will completely
drain from the condensate pan to comply with indoor air quali-
ty guidelines. The condensate drain pans are not insulated.
Step 6 — Make Electrical Connections
POWER WIRING — Units are factory wired for the voltage
shown on the unit nameplate.
Provide a unit safety disconnect switch in the main power
supply to each unit (see Fig. 15). Select switch size and mount-
ing location in accordance with applicable local codes or Na-
tional Electrical Code. If combining the functions of safety dis-
connect with Maximum Overcurrent Protection fuses (“fused
disconnect”), coordinate safety switch size with MOCP size
data as marked on unit informative plate.
Unit may be equipped with optional factory-installed Non-
Fused Disconnect switch (see Fig. 15). Provide Maximum
Overcurrent Protection devices (fuses or HACR breakers, per
local codes) in branch circuit wiring remote from unit. Observe
requirements of NEC Article 440. Install service switch up-
stream of remote fuses if required.
The main power terminal block is suitable for use with alu-
minum or copper wire. See Fig. 15. Units have circuit breakers
for compressors, fan motors, and control circuit. If required by
local codes, provide an additional disconnect switch. Whenev-
er external electrical sources are used, unit must be electrically
grounded in accordance with local codes, or in absence of local
codes, with NEC, ANSI (American National Standards Insti-
tute) C1-latest year.
FIELD POWER SUPPLY — Unit is factory wired for volt-
age shown on unit nameplate. See Table 4 for electrical data.
Field wiring can be brought into the unit from bottom
(through basepan and roof curb) or through side of unit (corner
post next to control box).
A 3
1
/
2
-in. NPT coupling for field power wiring and a
3
/
4
-in.
NPT coupling for 24-v control wiring are provided in basepan.
In the side post, there are two 2
1
/
2
-in. (50A020-035) or 3-in.
(50A040-060) knockouts for the field power wiring. See
Fig. 5-10. If control wiring is to be brought in through the side
of unit, a
7
/
8
-in. diameter hole is provided in the condenser side
post next to the control box.
If disconnect box is mounted to corner post, be careful not
to drill any screws into the condenser coil.
Routing Through Bottom of Unit — If wiring is brought in
through bottom of unit, use field-supplied watertight conduit to
run power wiring from basepan out through bottom 3
1
/
2
-in.
hole to the disconnect box and back into unit to the main
control box.
Use strain relief going into control box through 2
1
/
2
-in.
diameter hole provided. After wires are in unit control box,
connect to power terminal block (see Power Wiring section on
this page).
Low-voltage wiring must be run in watertight conduit from
the basepan to control box and through
7
/
8
-in. diameter hole
provided in bottom of unit control box. Field-supplied strain
relief must be used going into the box. After wiring is in
control box, make connections to proper terminals on terminal
blocks (see Field Control Wiring section on page 28).
Install conduit connector in unit basepan as shown in
Fig. 5-10. Route power and ground lines through connector to
terminal connections in unit control box as shown on unit
wiring diagram and Fig. 15.
Routing Through Side of Unit — Route power wiring in
field-supplied watertight conduit into unit through 2
1
/
2
-in. or
3-in. hole.
Use field-supplied strain relief going into control box
through 2
1
/
2
-in. or 3-in. diameter hole provided. After wires
are in unit control box, connect to power terminal block (see
Power Wiring section on this page).
Bring low-voltage control wiring through factory-drilled
7
/
8
-in. diameter hole in condenser side post. Use strain relief
going into
7
/
8
-in. diameter hole in bottom of unit control box.
Fig. 14 — Condensate Drain Trap Piping Details
(Typical Roof Curb or Slab Mount Shown)
Fig. 15 — Field Power Wiring Connections
FIELD SUPPLIED
DISCONNECT
PER NEC
FIELD
POWER
SUPPLY
11
21
22
23
13
12
TB1
EQUIP GND
FIELD POWER WIRING
11
21
22
23
13
12
GND
OPTIONAL
FACTORY-INSTALLED
DISCONNECT
FIELD-INSTALLED DISCONNECT
FACTORY-INSTALLED DISCONNECT
LEGEND
GND — Ground
NEC — National Electrical Code
TB — Terminal Block