System Requirements - Carrier 38MHR series Installation Instructions Manual

SYSTEM REQUIREMENTS

Allow sufficient space for airflow and service of the unit. See Fig. 5 for the required minimum distances between the unit, walls or ceilings.
Piping
IMPORTANT: Both refrigerant lines must be insulated separately.
S Table 3 contains piping information for the product covered within this document.
System Size
Min. Piping Length
Standard Piping Length
Max. outdoor-indoor
height difference (OU
higher than IU)
Max. outdoor-indoor
height difference (IU higher
than OU)
Max. Piping Length with
no additional refrigerant
charge per System
Piping
(Standard Piping length)
Total Max. Piping
Length per system
Additional refrigerant
charge (between Standard
– Max piping length)
Suction Pipe
(size - connection type)
Liquid Pipe
(size - connection type)
Refrigerant Type
Cooling Only Models
Charge Amount
Refrigerant
Heat Pump Models
Charge Amount
All outdoor units have an electronic expansion valve to manage the refrigerant flow of the fan coil connected.
Wiring
All wires must be sized per NEC (National Electrical Code) or
CEC (Canadian Electrical Code) and local codes. Use the Electrical
Data table MCA (minimum circuit amps) and MOCP (maximum
over current protection) to correctly size the wires and the
disconnect fuse or breakers respectively.
Per the caution note, only stranded copper conductors with a 600
volt rating and double insulated copper wire must be used. The use
of BX cable is not recommended.
Recommended Connection Method for Power and
Communication Wiring − Power and Communication Wiring:
The main power is supplied to the outdoor unit. The field supplied
14/3 power/communication wiring from the outdoor unit to the
indoor unit consists of four (4) wires and provides the power for
the indoor unit. Two wires are high voltage AC power, one is
communication wiring and the other is a ground wire.
Recommended Connection Method for Power and
Communication Wiring (To minimize communication wiring
interference) Power Wiring:
The main power is supplied to the outdoor unit. The field supplied
power wiring from the outdoor unit to the indoor unit consists of
three (3) wires and provides the power for the indoor unit. Two
wires are high voltage AC power and one is a ground wire. To
minimize voltage drop, the factory recommended wire size is 14/2
stranded with a ground.
Table 3—Piping and Refrigerant Information
9K (115V) 12V (115V)
ft. (m) 10(3) 10(3)
25(7.5) 25(7.5)
ft. (m)
33(10) 33(10)
ft. (m)
33(10) 33(10)
ft. (m)
ft. (m) 25(7.5) 25(7.5)
ft. (m) 82(25) 82(25)
Oz/ft
0.161(15) 0.161(15)
(g/m)
In (mm) 3/8(9.52) 1/2(12.7)
In (mm) 1/4(6.35) 1/4(6.35)
Type R410A R410A
Lbs (kg) 1.06(0.48) 1.30(0.59)
Lbs (kg) 1.76(0.8) 2.12(0.96)
9K (208-230V) 12K (208-230V)
10(3) 10(3)
25(7.5) 25(7.5)
33(10) 33(10)
33(10) 33(10)
25(7.5) 25(7.5)
82(25) 82(25)
0.161(15) 0.161(15)
3/8(9.52) 1/2(12.7)
1/4(6.35) 1/4(6.35)
R410A R410A
1.06(0.48) 1.30(0.59)
1.76(0.8) 2.12(0.96)
Communication Wiring:
A separate shielded stranded copper conductor only, with a 600
volt rating and double insulated copper wire, must be used as the
communication wire from the outdoor unit to the indoor unit.
Please use a separate shielded 16GA stranded control wire.
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
S Wires should be sized based on NEC and local codes.
S Use copper conductors only with a minimum 600 volt
rating and double insulated copper wire.
4
18 (208-230V) 24K (208-230V)
10(3) 10(3)
25(7.5) 25(7.5)
33(10) 33(10)
33(10) 33(10)
25(7.5) 25(7.5)
98(30) 164(50)
0.161(15) 0.322(30)
1/2(12.7) 5/8(15.9)
1/4(6.35) 3/8(9.52)
R410A R410A
2.09(0.95) 2.65(1.2)
3.30(1.5) 3.968(1.8)