Carrier 38AUQ*07-12 Piping Recommendations Single-Circuit Unit, Maximum Vertical Separation

Table 2 — 38AUQ*07-12 Piping Recommendations (Single-Circuit Unit)

R-410A				Equivalent Length
	Ft	0-38		38-75	75-113		113-150
Model	Length Linear	0-25		25-50	50-75		75-100
Nominal Capacity	Length Equiiv	0-38		38-75	75-113		113-115
38AUQ*07	Liquid Line	3/8		3/8	3/8	1/2	3/8	1/2
	Max Lift	25		50	48	75	39	100
	Cool
	Heat	25		50	46	60	31	60
	Suction Line	7/8		7/8	1-1/8		1-1/8
	Charge (lbs)	17.8		18.8	20.3	22.6	21.4	24.5
38AUQ*08	Liquid Line	1/2		1/2	1/2		1/2
	Max Lift	25		50	75		100
	Cool
	Heat	25		50	60		60
	Suction Line	7/8	1-1/8	1-1/8	1-1/8		1-1/8
	Charge (lbs)	20.9		23.0	24.9		26.8
38AUQ*12	Liquid Line	1/2		1/2	1/2		1/2	5/8
	Max Lift	25		50	75		85	100
	Cool
	Heat	25		50	60		60	60
	Suction Line	7/8	1-1/8	1-1/8	1-1/8		1-1/8	1-3/8
	Charge (lbs)	26.8		28.8	30.7		33.4	37.2
Legend:
Length Equiv	Equivalent tubing length, including effects of refrigeration specialties devices
Liquid Line	Tubing size, inches OD.
Max Lift	Maximum liquid lift at maximum permitted liquid line pressure drop
Cooling	• Indoor unit ABOVE outdoor unit
Heating	• Indoor unit BELOW outdoor unit
Suction Line	Tube size, inches OD
Charge	Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger
	suction line size (where applicable)
NOTE:	For applications with linear length greater than 100 ft (30.5 m), contact your local Carrier representative.

CHECK VERTICAL SEPARATION — If there is any vertical separation between the indoor and outdoor units, check to ensure that the separation is within allowable limits. Relocate equipment if necessary.

PROVIDE SAFETY RELIEF — If local codes dictate an additional safety relief device, purchase locally and install locally. Installation will require the recovery of the factory shipping charge before the factory tubing can be cut and the supplemental relief device is installed.

REFRIGERANT LINE SIZING — Consider the length of the piping required between the outdoor and indoor units. The maximum allowable line length is 100 ft (30.5 m). See Table 2. Refrigerant vapor piping should be insulated.

IMPORTANT: A refrigerant receiver is not provided with the unit. Do not install a receiver.

Table 3 — Maximum Vertical Separation*

UNIT 38AUQ	UNIT 40RUQ	DISTANCE FT (M)
		Unit 38AUQ
		Above Unit 40RMQ
07	07	50 (15.2)
08	08	60 (18.3)
12	12	60 (18.3)

*Vertical distance between indoor and outdoor units.

INSTALL FILTER DRIER(S) AND MOISTURE INDICATOR(S) — Every unit MUST have a bi-directional filter drier in the liquid line. Locate the filter drier at the indoor unit, close to the evaporator coil’s thermal expansion valve (TXV) inlets.

38AUQ units include one Puron-duty filter drier, shipped in cartons attached to the unit basepan. Remove the filter drier and prepare to install in the liquid line at the evaporator coil. Do not remove connection fitting plugs until ready to connect and braze the filter drier into the liquid line position.

Table 4 — Puron-duty Filter Drier(s)

Model-Size	Qty	Liquid	Desiccant	Part
		Line OD	Volume	Number Ref
38AUQ*07	1	3/8-in	8 cu. in.	KH43LG091
38AUQ*08	1	1/2-in	16 cu. in.	KH43LG085
38AUQ*12	1	1/2-in	16 cu. in.	KH43LG085

Installation of liquid line moisture indicating sightglass in each circuit is recommended. Locate the sightglass(es) between the outlet of the filter drier and the TXV inlet.

Refer to Table 5 for recommendations on refrigeration specialties.

Select the filter drier for maximum unit capacity and minimum pressure drop. Complete the refrigerant piping from the indoor unit to the outdoor unit before opening the liquid and suction lines at the outdoor unit.

8