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8

screwed or bolted to duct flanges. Use suitable gaskets to
ensure weather--tight and airtight seal.

4. All units must have field--supplied filters or accessory filter

rack installed in the return--air side of the unit.
Recommended sizes for filters are shown in Table 1.

5. Size all ductwork for maximum required airflow (either

heating or cooling) for unit being installed. Avoid abrupt

duct size increases or decreases or performance may be
affected.

6. Adequately insulate and weatherproof all ductwork located

outdoors. Insulate ducts passing through unconditioned
space, and use vapor barrier in accordance with latest issue

of Sheet Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
of America (ACCA) minimum installation standards for

heating and air conditioning systems. Secure all ducts to
building structure.

7. Flash, weatherproof, and vibration--isolate all openings in

building structure in accordance with local codes and good

building practices.

A

B

C

MAXIMUM ALLOWABLE

DIFFERENCE in. (mm)

A-C

1/4

1/4

1/4

(6.35)

(6.35)

(6.35)

A-B

B-C

A07925

Fig. 7 -- Unit Leveling Tolerances

OPTIONAL

RETURN

AIR

OPENING

OPTIONAL

SUPPLY

AIR

OPENING

EVAP. COIL

COND. COIL

(50.8mm)

A07926

Fig. 8 -- Slab Mounting Detail

Step 6 — Provide for Condensate Disposal

NOTE

: Ensure that condensate--water disposal methods comply

with local codes, restrictions, and practices.
The 50VT--A units dispose of condensate through a 3/4 in. NPT

female fitting that exits on the compressor end of the unit.

Condensate water can be drained directly onto the roof in rooftop
installations (where permitted) or onto a gravel apron in ground

level installations. Install a field--supplied condensate trap at end of
condensate connection to ensure proper drainage. Make sure that

the outlet of the trap is at least 1 in. (25 mm) lower than the
drain--pan condensate connection to prevent the pan from

overflowing. Prime the trap with water. When using a gravel apron,

make sure it slopes away from the unit.
If the installation requires draining the condensate water away from

the unit, install a field--supplied 2 --in. (51mm) trap at the
condensate connection to ensure proper drainage. Condensate trap

is available as an accessory or is field--supplied. Make sure that the

outlet of the trap is at least 1 in. (25 mm) lower than the unit
drain--pan condensate connection to prevent the pan from

overflowing. Connect a drain tube using a minimum of
field--supplied 3/4--in. PVC or field--supplied 3/4--in. copper pipe

at outlet end of the 2--in. (51 mm) trap. (See Fig. 9) Do not

undersize the tube. Pitch the drain tube downward at a slope of at

least 1 in. (25 mm) every 10 ft (3 m) of horizontal run. Be sure to
check the drain trough for leaks. Prime the trap at the beginning of

the cooling season start--up.

TRAP
OUTLET

1-in. (25 mm) min.

2-in. (51 mm) min.

A09052

Fig. 9 -- Condensate Trap

Step 7 — Install Electrical Connections

UNIT COMPONENT DAMAGE HAZARD

Failure to follow this caution may result in damage to the unit

being installed.

1. Make all electrical connections in accordance with NEC

NFPA 70 (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical

connections must be in accordance with CSA standard
C22.1 Canadian Electrical Code Part 1 and applicable
local codes. Refer to unit wiring diagram.

2. Use only copper conductor for connections between

field--supplied electrical disconnect switch and unit. DO

NOT USE ALUMINUM WIRE.

3. Be sure that high--voltage power to unit is within

operating voltage range indicated on unit rating plate. On

3--phase units, ensure phases are balanced within 2
percent. Consult local power company for correction of

improper voltage and/or phase imbalance.

4. Do not damage internal components when drilling

through any panel to mount electrical hardware, conduit,
etc.

!

CAUTION

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury

or death.
The unit cabinet must have an uninterrupted, unbroken

electrical ground. This ground may consist of an electrical

wire connected to the unit ground screw in the control

compartment, or conduit approved for electrical ground when

installed in accordance with NEC,NFPA 70 National Fire

Protection Association (latest edition) (in Canada, Canadian

Electrical Code CSA C22.1) and local electrical codes.

!

WARNING

High--Voltage Connections

The unit must have a separate electrical service with a

field--supplied, waterproof disconnect switch mounted at, or within

sight from the unit. Refer to the unit rating plate, NEC and local
codes for maximum fuse/circuit breaker size and minimum circuit

amps (ampacity) for wire sizing.
The field--supplied disconnect may be mounted on the unit over

the high--voltage inlet hole when the standard power and

low--voltage entry points are used. See Fig. 2 and 3 for acceptable
location. Remove high voltage knockout.
See unit wiring label (Fig. 12--14) and Fig. 10 for reference when
making high voltage connections. Proceed as follows to complete

the high--voltage connections to the unit.

50V

T

--

A

Summary of Contents for COMFORT 50VT-A

Page 1: ...ndensate Drain Pan 26 Outdoor Fan 26 Electrical Controls and Wiring 26 Refrigerant Circuit 26 Indoor Airflow 26 Metering Devices TXV Piston 26 Pressure Switches 27 Loss of Charge Switch 27 High Pressu...

Page 2: ...tructions shipped with curb See Fig 4 Install insulation cant strips roofing and flashing Ductwork must be attached to curb IMPORTANT The gasketing of the unit to the roof curb is critical for a water...

Page 3: ...3 A09410 Fig 2 50VT A24 30 Unit Dimensions 50VT A...

Page 4: ...4 A09411 Fig 3 50VT A36 60 Unit Dimensions 50VT A...

Page 5: ...mm B small common base IN mm B large base IN mm C IN mm D IN mm E IN mm F IN mm G IN mm H IN mm Small or Large CPRFCURB010A00 11 279 10 254 14 356 16 406 47 8 1214 32 4 822 2 7 69 30 6 778 46 1 1170 C...

Page 6: ...adapt to various sizes or kinds of loads 2 Instruction in any special operation or precaution 3 Condition of the load as it relates to operation of the lifting kit such as balance temperature etc Foll...

Page 7: ...commended 4 Seal insulate and weatherproof all external ductwork Seal insulate and cover with a vapor barrier all ductwork passing through conditioned spaces Follow latest Sheet Metal and Air Conditio...

Page 8: ...be using a minimum of field supplied 3 4 in PVC or field supplied 3 4 in copper pipe at outlet end of the 2 in 51 mm trap See Fig 9 Do not undersize the tube Pitch the drain tube downward at a slope o...

Page 9: ...o that they do not interfere with operation of unit A gray wire is standard on 3 phase units for connection to an economizer If an accessory electric heater is installed low voltage leads from heater...

Page 10: ...1000 10 x 10 254 x 254 1 2 1200 11 x 10 279 x 254 3 4 1400 11 x 10 279 x 254 3 4 1600 11 x 10 279 x 254 1 1750 11 x 10 279 x 254 1 High Pressure Switch psig Cutout Reset Auto 650 15 420 25 Loss of Cha...

Page 11: ...11 A11002 Fig 12 Connection Wiring Schematics 208 230 1 60 50VT A...

Page 12: ...12 A11001 Fig 12 Cont Ladder Wiring Schematics 208 230 1 60 50VT A...

Page 13: ...13 A11006 Fig 13 Connection Wiring Schematics 208 230 3 60 50VT A...

Page 14: ...14 A11005 Fig 13 Cont Ladder Wiring Schematics 208 230 3 60 50VT A...

Page 15: ...15 A10195 Fig 14 Connection Wiring Diagram 460 3 60 50VT A...

Page 16: ...16 A10195 Fig 14 Cont Ladder Wiring Diagram 460 3 60 50VT A...

Page 17: ...P Checking Cooling and Heating Control Operation Start and check the unit for proper control operation as follows 1 Place room thermostat SYSTEM switch or MODE control in OFF position Observe that blo...

Page 18: ...uctions and adjusted properly ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in personal injury or death Disconnect electrical power to the unit and install lockout tag before cha...

Page 19: ...ressure 3 Select speed tap from Table 4 that will achieve required airflow from Table 2 4 Remove the vinyl cap off of the desired speed tap wire Refer to Table 3 for color coding 5 Connect the desired...

Page 20: ...he Heating mode Defrost The defrost control is a time temperature control which includes a field selectable time period DIP switch 1 and 2 on the board between defrost cycles of 30 60 90 or 120 minute...

Page 21: ...ack cfm 2461 2409 2339 2286 2192 2140 2062 1968 1874 50VT A60 Low Blue cfm 1445 1389 1341 1281 1236 1189 1139 1072 1027 Med Low Pink cfm 1678 1635 1602 1558 1513 1474 1438 1404 1349 Medium 1 Red cfm 1...

Page 22: ...0 10 0 12 0 13 0 15 0 17 0 18 0 20 0 23 Table 9 Electric Heat Pressure Drop Table in W C Small Cabinet 24 36 STATIC STANDARD CFM SCFM 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 5kw 0 00 0...

Page 23: ...air filter s at least once each month and replace throwaway type or clean cleanable type at least twice during each cooling season and twice during the heating season or whenever the filter becomes cl...

Page 24: ...24 A09412 Fig 18 Cooling Charging Table Subcooling 50VT A...

Page 25: ...OF2 OF1 ON QUIET SHIFT 120 30 60 60 30 90 INTERVAL TIMER OFF P3 DFT O R W 2 Y C T2 C C O DFT T1 Y P1 J1 SPEEDUP Speedup Pins Defrost interval DIP switches Quiet Shift A08020 Fig 19 Defrost Control 50V...

Page 26: ...trical Controls and Wiring Inspect and check the electrical controls and wiring annually Be sure to turn off the electrical power to the unit Remove access panels see Fig 22 to locate all the electric...

Page 27: ...gerant System This step covers the refrigerant system of the 50VT A including the compressor oil needed servicing systems on roofs containing synthetic materials the filter drier and refrigerant charg...

Page 28: ...ch must be removed remove and recover all system charge so that pressure gauges read 0 psig Never open system without breaking vacuum with dry nitrogen Check Defrost Thermostat The defrost thermostat...

Page 29: ...ils S Vacuum pumps will not remove moisture from oil S Do not use liquid line filter driers with rated working pressures less than 600 psig S Do not leave Puron suction line filter driers in line long...

Page 30: ...efective run start capacitor overload or start relay Determine cause and replace Defective thermostat Replace thermostat Faulty condenser fan motor or capacitor Replace Restriction in refrigerant syst...

Page 31: ...D IN PLACE VERIFY THAT UNIT INSTALLATION IS LEVEL CHECK FAN WHEEL AND PROPELLER FOR LOCATION IN HOUSING ORIFICE AND SETSCREW TIGHTNESS III START UP ELECTRICAL SUPPLY VOLTAGE COMPRESSOR AMPS INDOOR EVA...

Page 32: ...S 7310 W Morris St S Indianapolis IN 46231 Edition Date 01 11 Manufacturer reserves the right to change at any time specifications and designs without notice and without obligations Catalog No 50VT 0...

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