York E1FB240, E1FB180 Refrigerant Piping, SUCTION LINES 1,2, General Guidelines, Service Valves

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TABLE 4 - SUCTION LINES 1,2
	Model		Nominal	Refrigerant	Type L	Friction
			Capacity	Flow Rate3	Copper Tubing	Loss4,5
	Designation		(Tons)	(Lbs./Min.)	(Inches O.D.)	(PSI/100 Ft.)
180		System 1	7-1/2	22.5	1-1/8	4.7
		System 2	7-1/2	22.5	1-1/8	4.7
240		System 1	10	30	1-3/8	2.8
		System 2	10	30	1-3/8	2.8

1All horizontal suction lines should be pitched at least 1 inch every 20 feet in the direction of the refrigerant flow to aid the return of oil to the compressor.

2Every vertical suction riser greater than 25 feet in height should have a “P” trap at the bottom to facilitate the return of oil to the compressor. Use short radius fittings for these traps.

3Based on Refrigerant-22 at the nominal capacity of the condensing unit, a suction temperature of 40°F and a liquid temperature of 105°F.

4Although suction lines should be sized for a friction loss equivalent to a 2°F change in saturation temperature (or approximately 3 psi), sizing the lines for the proper return of oil is more important.

5These friction losses do not include any allowances for valves or fittings.

6Since the refrigerant gas velocity may be too low to maintain good oil return up a vertical riser, use the next smaller size. The larger size may be used for horizontal runs for a smaller pressure drop.

and/or drafts. Circulation of air to the thermostat should not be blocked by curtains, drapes, furniture, partitions, etc.

Some installations may require a locking cover to protect the

thermostat from tampering and/or damage.

Both the manual and the auto changeover thermostats have non-adjustable, voltage-type anticipators for both cooling and heating.

REFRIGERANT PIPING

GENERAL GUIDELINES

Many service problems can be avoided by taking adequate precautions to provide an internally clean and dry system and by using procedures and materials that conform with es- tablished standards.

Use hard drawn copper tubing where no appreciable amount of bending around pipes or other obstructions is necessary. Use long radius ells wherever possible with one exception - small radius ells for the traps in all vapor risers. If soft copper is used, care should be taken to avoid sharp bends which may cause a restriction.

Pack fiber glass insulation and a sealing material such as permagum around refrigerant lines where they penetrate a wall to reduce vibration and to retain some flexibility.

Support all refrigerant lines at minimum intervals with suitable hangers, brackets or clamps.

Braze all copper to copper joints with Sil Fos-5 or equivalent brazing material. Do not use soft solder.

Insulate all vapor lines with a minimum of 1/2" ARMA-FLEX or equal. Liquid lines exposed to direct sunlight and/or high tem- peratures must also be insulated.

Never solder vapor and liquid lines together. They can be taped together for convenience and support purposes, but they must be completely insulated from each other.

LINE SIZING

When sizing refrigerant lines for a split-system air conditioner, check the following:

1.Suction line pressure drop due to friction at full capacity,

2.Liquid line pressure drop due to friction at full capacity,

3.Suction line velocity for oil return at part capacity, and

4.Liquid line pressure drop due to static head.

NOTE: Never base refrigerant line sizes on the OD of the suc- tion and liquid connections on the unit.

Tables 4 and 5 list friction losses for both the suction and liq- uid lines on the system. Table 6 shows the amount of refrig- erant charge required per foot of refrigerant line.

When the evaporator coil is below the condensing unit, the suction line must be sized for both pressure drop and for oil return. For certain piping arrangements, different suction line sizes may have to be used. The velocity of the suction gas must always be great enough to carry oil back to the compressor.

When the condensing unit is below the evaporator coil, the liquid line must be designed for the pressure drop due to both friction loss and vertical rise. If the total pressure drop exceeds 40 psi, some refrigerant may flash before it reaches the thermal expansion valve. This flashing will not only cause erratic valve operation and poor system performance, but could also damage the expansion valve.

SERVICE VALVES

These outdoor units have both vapor and liquid line service

valves.

Both valves are shipped from the factory front-seated and closed with the valve stem in the maximum clockwise posi- tion.

These service valves are the back-seating type and have a 1/4" male flare access port for evacuating and charging the system.

Shrader access valves are provided on the compressor va- por and discharge lines for pressure checking the system.

All access ports are sealed with a removable cap. Never re- move a cap unless the valve is fully back-seated with its valve stem in the maximum counter-clockwise position be- cause the refrigerant charge will be lost.

INSTALLATION

Since these units are shipped with a holding charge of Refrigerant-22, they can be checked for a refrigerant leak by opening the access port on the liquid line service valve as fol- lows:

Open the valve by turning the1. stem to its maximum counter- clockwise position.

Remove the cap from the 2access. port.

WARNING: Provisions for recovering refrigerant releases must be available during all phases of installa- tion, leak testing and charging. Do NOT re- lease refrigerant into the atmosphere.

Unitary Products Group 7