Guide Specifications Ð 579F180-300

H.Filter Section:

Standard ®lter section shall consist of 2 sizes of factory- installed 2-in. thick throwaway ®berglass ®lters of commercially available sizes.

I.Controls and Safeties:

1.Unit Controls:

a.Economizer control (optional)

b.Capacity control (2-step)

c.Unit shall be complete with self-contained low- voltage control circuit.

2.Safeties:

a.Unit shall incorporate a solid-state compressor lockout which provides reset capability at the space thermostat, should any of the following safety devices trip and shut off compressor:

1)Compressor overtemperature, overcurrent.

2)Low-pressure switch.

3)Freezestats (evaporator coil).

4)High-pressure switch.

b.Supply-air thermostat shall be located in the unit.

c.Heating section shall be provided with the follow- ing minimum protections:

1)High-temperature limit switch.

2)Induced-draft motor speed sensor.

3)Flame rollout switch.

4)Flame proving controls.

5)Redundant gas valve.

J.Operating Characteristics:

1.Unit shall be capable of starting and running at 115 F ambient outdoor temperature per maximum load crite- ria of ARI Standard 360.

2.Unit with standard controls will operate in cooling down to an outdoor ambient temperature of 40 F on 579F180 units, to 35 F on 216 units, to 25 F ambient on 240 units, and to 48 F ambient on 300 units.

3.Unit shall be provided with fan time delay to prevent cold air delivery.

K.Electrical Requirements:

All unit power wiring shall enter unit cabinet at a single location.

L.Motors:

1.All compressor motors shall be of the refrigerant cooled type with thermal and calibrated circuit breaker overload protection.

2.All fan motors shall have permanently lubricated, sealed bearings and inherent automatic-reset thermal overload protection or manual reset calibrated circuit breakers.

3.All indoor-fan motors 5 hp and larger shall meet the minimum ef®ciency requirements as established by the Energy Policy Act of 1992 (EPACT) effective Oc- tober 24, 1997.

1.Roof Curbs (Horizontal and Vertical):

a.Formed of 18-gage galvanized steel with wood nailer strip and shall be capable of supporting en- tire unit weight.

b.Permits installing and securing ductwork to curb prior to mounting unit on the curb.

2.Horizontal Adapter Roof Curb:

Includes factory-assembled adapter and duct and substantially improves evaporator fan static performance.

*3. Integrated Economizer:

a.Integrated type capable of simultaneous econo- mizer and compressor operation to provide cool- ing with outdoor air.

b.Equipped with low-leakage dampers not to exceed 3% leakage, at 1.0 in. wg pressure differential.

c.Capable of introducing up to 100% outdoor air.

d.Equipped with dry-bulb temperature control to govern economizer changeover.

e.Equipped with a mixed-air sensor that controls the economizer to a 55 F control point.

4.Two-Position Damper:

Two-position damper package shall include single blade damper and motor. Admits up to 25% outdoor air, and shall close upon unit shutoff.

5.Accessory Compressor Cycle Delay:

Compressor shall be prevented from restarting for a minimum of 5 minutes after shutdown.

*6. Thermostats and Subbases:

To provide staged heating and cooling in addition to automatic (or manual) changeover and fan control.

*7. Barometric Relief Damper Package:

a.Package shall include damper, seals, hardware, and hoods to relieve excess internal pressure.

b.Damper shall close due to gravity upon unit shut- down.

*8. Power Exhaust:

Package shall include an exhaust (propeller style) fan, 1¤2 Hp 208-230, 460 v (factory-wired for 460 v) motor, and damper for vertical ¯ow units with econo- mizer to control overpressurization of building.

*9. Head Pressure Control Package:

Consists of an accessory outdoor-air package and a solid-state control with condenser coil temperature sensor for controlling condenser-fan motor speed to maintain condensing temperature between 90 F and 100 F at outdoor ambient temperature down to ±20 F.

10.Low-Ambient Kits:

When used, allows units to operate at lower outdoor ambient temperatures. See trade prices for more information.

M.Special Features:

Certain features are not applicable when the features designated * are speci®ed. For assistance in amending the speci®cations, contact your local sales of®ce.