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c. This gauge access port shall facilitate correct and accurate condenser pressure readings by enabling the
reading with the compressor access panel on.
d. The plug shall be made of a leak proof, UV--resistant, composit e material .
3. Compressors
a. Unit shall use fully hermetic, scroll compressor for each independent refrigera tion circuit.
b. Compressor motors shall be cooled by refrigerant gas passing through m otor windings.
c. Compressors shall be internally protected from high discharge temperature conditions.
d. Compressors shall be protected from an over--temperature and over--amperage conditions by an internal,
motor overload devi ce.
e. Compressor shall be factory mounted on rubbe r grommets.
f. Compressor motors shall have internal line break therm al, current overload and high pressure differential
protec tion.
g. Crankcase heaters shall not be required for norm al operating range, unless requi red by compre ssor ma nufac-
turer due to refrigerant charge limits.
23 81 19.13.L. Filter Section
1. Filters access is specified in the unit cabinet section of this specification.
2. Filters shall be held in place by a pivoting filter tray, facilitating easy removal and installation.
3. Shall consist of factory installed, low velocity, throw--away 2 --in. thick fiberglass filters.
4. Filters shall be standard, commercially available sizes.
5. Only one size filter per unit is allowed.
23 81 19.13.M. Evaporator Fan and Motor
1. Evaporator fan motor:
a. Shall have permanently lubricated bearings.
b. Shall have inherent automatic --reset thermal overload protection or circuit breaker.
c. Shall have a maximum continuous bhp rating for continuous duty operation; no safety factors above that
rating shall be required.
2. Belt--driven Evaporator Fan:
a. Belt drive shall include an adjustable pitch motor pulley.
b. Shall use sealed, permanently lubricated ball -- bearing type.
c. Blower fan shall be double--inlet type with forward--curved blades.
d. Shall be constructed from steel with a corrosion resistant finish and dynamically balanced.
23 81 19.13.N. Condenser Fans and Motors
1. Condenser fan motors:
a. Shall be a totally enclosed motor.
b. Shall use permanently lubricated bearings.
c. Shall have inherent thermal overload protection with an automatic reset feature.
d. Shall use a shaft--down design on 04 to 12 and 16 model s a nd shaft--up on 14 size with rain shield.
2. Condenser Fans:
a. Shall be a direct--driven prope ller type fan.
b. Shall have galvalum blades rivet ed to corrosion--resista nt steel spiders and shall be dynamically ba lance d.
23 81 19.13.O. Special Features Options and Accessories
1. Staged Air Volume System (SAV) for 2--stage cooling models only:
a. Evaporator fan motor:
(1.) Shall have permanently lubricated bearings.
(2.) Shall ha ve a ma ximum continuous bhp rati ng for continuous duty ope ration; no safety fac tors above
that rating.
(3.) Shall be Variable Frequency duty and 2--speed control.
(4.) Shall c ontain m otor shaft grounding ri ng to prevent electrical bearing fluting damage by safely diver t-
ing harmful shaft voltages and bearing currents t o ground.
2. Variable Frequency Drive (VFD). Only ava ilable on 2--speed indoor fan motor option (SAV):
a. Shall be installed inside the unit cabinet, mounted, wired and tested.
b. Shall contain Electromagnetic Int erference (EMI) frequency protection.
c. Insulated Gate Bi--Polar Transistors (IGBT) used to produce the output pulse width modulat ed (PWM)
waveform, allowing for quiet motor operation.
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