Bryant R-22 Ix. Wind Baffle, X. Coastal Filter, Xi. Support Feet, Xii. Liquid-Linesolenoid Valve

TABLE 1—REQUIRED FIELD-INSTALLED ACCESSORIES FOR AIR CONDITIONERS AND HEAT PUMPS

	REQUIRED FOR	REQUIRED FOR	REQUIRED FOR
ACCESSORY	LOW-AMBIENT	LONG-LINE	SEA COAST
	APPLICATIONS	APPLICATIONS*	APPLICATIONS
	(BELOW 55°F)	(OVER 50 FT)	(WITHIN 2 MILES)
Crankcase Heater	Yes	Yes	No
Evaporator Freeze Thermostat	Yes	No	No
Winter Start Control	Yes†	No	No
Accumulator	No	No	No
Compressor Start Assist	Yes	Yes	No
Capacitor and Relay
Low Ambient Controller,
MotorMaster™ Control,	Yes	No	No
or
Low-Ambient Pressure Switch
Wind Baffle	See Low-Ambient Instructions	No	No
Coastal Filter	No	No	Yes
Support Feet	Recommended	No	Recommended
Liquid-Line Solenoid Valve		See Long-Line
or	No	Application	No
Hard-Shutoff TXV		Guideline
Ball-Bearing Fan Motor	Yes‡	No	No
Isolation Relay	Yes**	No	No

*For tubing line sets between 50 and 175 ft, refer to Residential Split-System Long-Line Application Guideline. †Only when low-pressure switch is used.

‡Required for Low-Ambient Controller (full modulation feature) and MotorMaster™ control only. ** Required on Heat Pumps only.

IX. WIND BAFFLE

A field-fabricated sheet-metal cover used to stop prevailing winds or where outdoor ambient temperature is less than 55°F during unit operation of cooling mode.

X. COASTAL FILTER

A mesh screen inserted under top cover and inside base pan to protect condenser coil from salt damage without restricting air- flow.

XI. SUPPORT FEET

Four adhesive plastic feet which raise unit 4 in. above mounting pad. This allows sand, dirt, and other debris to be flushed from unit base; minimizes corrosion.

XII. LIQUID-LINE SOLENOID VALVE

An electrically operated shutoff valve to be installed at outdoor or indoor unit (depending on tubing configuration) which stops and starts refrigerant liquid flow in response to compressor operation. Maintains a column of refrigerant liquid ready for action at next compressor-operation cycle and prevents liquid migration during the off cycle.

XIII. THERMOSTATIC-EXPANSION VALVE

A modulating flow-control device which meters refrigerant flow rate into the evaporator in response to the superheat of the refrigerant gas leaving the evaporator. Only use factory-specified TXV’s.

XIV. ISOLATION RELAY

A DPDT relay which switches the low-ambient controller out of the outdoor fan-motor circuit when the heat pump switches to heating mode.

LOW-AMBIENT GUIDELINE

The minimum operating temperature for these units in cooling mode is 55°F outdoor ambient without additional accessories. This equipment may be operated in cooling mode at ambient tempera- tures below 55°F when the accessories listed in Table 1 are installed. Wind baffles are required when operating in cooling mode at ambients below 55°F. Refer to Fig. 1 or 2 and Table 2 or 3 for wind baffle construction details.

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LONG-LINE GUIDELINE

This Long-Line Application Guideline applies to all Bryant residential air conditioner and heat pump split systems that have a nominal capacity of 18,000 to 60,000 Btuh. This guideline provides required system changes and accessories necessary for any residential product having piping requirements greater than 50 ft or installations where indoor unit is located above outdoor unit. This guideline is intended to cover applications outside the standard Installation Instructions. This guideline is for standard, single-speed products. For applications involving 2-speed prod- ucts, refer to Section VI first.

NOTE: The presale literature for outdoor unit must be referred to in conjunction with this guideline.

I. APPROVED SYSTEMS

Any residential indoor/outdoor unit combination listed in the outdoor unit presale literature is an approved system, EXCEPT the following:

•Indoor coils with capillary-metering devices

•All equipment less than nominal 18,000 Btuh

•All 1/4-in. and 5/16–in. liquid-line applications

•Any indoor furnace coil/fan coil not listed in outdoor unit presale literature

•Any application which has interconnecting tubing with an equivalent length greater than 175 ft

II. INTERCONNECTING TUBING SIZING

Table 4 lists recommended interconnecting vapor-line diameters for equivalent total-line lengths. All residential split systems installed in long-line applications must use only 3/8-in. liquid lines. Equivalent line length equals the linear length (measured) of interconnecting vapor tubing plus losses due to elbows. (See Table 5 and Fig. 3.) Liquid lines larger than 3/8-in. OD greatly increase charge quantity of the system. Excessive charge increases risk of migration and compressor damage. Table 4 provides the estimated percentage of nominal cooling-capacity losses based on the stan- dard, required vapor line size versus what is selected for the long-line application. Since the vapor line is the discharge line in heating mode, losses are minimal.