background image

After the movable flange (or flanges) has been rotated to the
proper number of “turns open”, the set screws should be
tightened against the flats on the barrel to lock the movable
flange in place. If the pulley includes a locking collar, the locking
collar must be loosened to adjust the setting of the movable
flange.

Note the following:

1. The supply air CFM must be within the limitations shown in

Table 1.

2. Both movable flanges on a 2-groove pulley must be

adjusted to the same setting (turns open) to balance the
loading on both belts.

3. All pulleys can be adjusted in half-turn increments.

4. The tension on each belt shall be adjusted per the following

procedure. See Figure 16.

a. Loosen two nuts (A).

b. Adjust by turning (B).

c. Never loosen nuts (C).

d. Using a belt tension checker, apply a perpendicular

force to one belt at the midpoint of the span as shown.
The deflection force should be applied until the speci-
fied deflection distance is obtained.

The deflection distance equals 1/64" per inch of span
length.

To determine the deflection distance from normal posi-
tion use a straight edge from sheave to sheave as a
reference line.

The recommended deflection force is as follows:

e. Tension new belts at the maximum deflection force

recommended for the belt section. Check the belt ten-
sion at lease two times during the first 24 hours of
operation. Any retensioning should fall between the
minimum and maximum deflection force values.

f.

After adjusting, retighten nuts (A).

5. All pulleys are factory aligned.

6. All supply air motor pulleys are factory set at 2 “turns open”.

After the pre-start check list has been completed:

1. Start the supply air blowers.

2. Adjust the resistances in both the supply and the return duct

systems to balance the air distribution throughout the
conditioned space. The job specifications may require that
this balancing be done by someone other than the
equipment installer.

To check the supply air CFM after the initial balancing has been
completed.

1. Drill two 5/16" holes (A & B) as shown in Figure 17.

MODEL

TURNS

OPEN

1

RPM

10

15

20

DSC360

6

780

924

-

5

812

962

-

4

844

1000

-

3

876

1038

-

2

908

1076

-

1

940

1114

-

DSC480

6

-

924

-

5

-

962

-

4

-

1000

-

3

-

1038

-

2

-

1076

-

1

-

1114

1189

2

1

Pulleys can be adjusted in half turn increments.

2

Fixed pulleys, no adjustment.

TABLE 7 - SUPPLY AIR SYSTEM ADJUSTMENT

BELT

SECTION

DEFLECTION FORCE (LBS.)

MINIMUM

MAXIMUM

“B”

4

5

“C”

11

14

FIG. 16 - TYPICAL MOTOR MOUNTING ASSEMBLY

530.25-N3Y

Unitary Products Group

17

Содержание D*SC360

Страница 1: ...te request for inspection by the carrier s agent should be made in writing Refer to Form 50 15 NM for additional information REFERENCE Additional information on the design installation operation and service of this equipment is available in the following reference forms 55 70 N1 General Installation 55 70 N2 Pre start Post start Check List Renewal Parts Refer to the Renewal Parts Manual for comple...

Страница 2: ...ta 21 10 Resistances Unit Options Accessories 21 11 Supply Air Blower Performance 22 FIGURES No Description Page 1 Unit Less Panels 3 2 Typical Rigging 3 3 Center of Gravity 3 4 Recommended Drain Piping 4 5 Bottom Power Wiring Entrance 5 6 Side Power Wiring Entrance 5 7 Control Wiring Entrance DSC360 6 8 Control Wiring Entrance DSC480 6 9 Control Wiring Conns w o Status Panel 7 10 Control Wiring C...

Страница 3: ... mounting curbs capable of supporting the unit s weight may also be field fabricated CLEARANCES These units must be installed with the minimum clearances listed below A 2 clearance within 3 feet of the unit must be maintained between any combustible material and the supply air duct work No objects should be left near the combustion air inlet to obstruct the openings If the unit is slab mounted shr...

Страница 4: ... 90 degrees clockwise to facilitate entrance of the power wiring from the side of the box To do this remove the 1 4 bolt holding the power lug Next remove the slotted spring pin which keeps the lug from rotating Turn the power lug 90 degrees clockwise and replace both the slotted spring pin and the 1 4 bolt MODEL DSC 360 480 Voltage Variation Min Max1 200 Volts 187 218 230 Volts 216 252 460 Volts ...

Страница 5: ...s the power wiring is already above the finished roof 2 Units that are mounted on structural steel above the finished roof unless the steel is blocking the 4 1 2 diameter sleeve in the base of the unit This applies to units with or without a factory installed disconnect switch CAUTION The 4 1 2 sleeve must be sealed after the power wiring has been routed to prevent pos sible condensation problems ...

Страница 6: ...ugh the side entry must be sealed to prevent the entrance of water CONTROL WIRING MODEL DSC480 For bottom entry Figure 8 the control wiring should be routed 1 Up through the 2 1 4 O D tubing behind the control box 2 Through the positioned ty wrap on the outside of the control box 3 Through the 1 3 8 snap bushing in the control box 4 Through the 2 ty wraps positioned in the control box 5 Connect th...

Страница 7: ...FIG 9 CONTROL WIRING CONNECTIONS WITHOUT STATUS PANEL 530 25 N3Y Unitary Products Group 7 ...

Страница 8: ...FIG 10 CONTROL WIRING CONNECTIONS WITH STATUS PANEL 530 25 N3Y 8 Unitary Products Group ...

Страница 9: ...FIG 11 CONTROL WIRING CONNECTIONS SOLID STATE CONTROL WITH STATUS PANEL FIG 12 CONTROL WIRING CONNECTIONS SOLID STATE CONTROL WITH STATUS PANEL 530 25 N3Y Unitary Products Group 9 ...

Страница 10: ...air fans 4 Based on three 75ÉC insulated copper conductors in steel conduit 2 Rated at a 45ÉET and a 130ÉCT 5 Based on a 3 voltage drop 3 Dual element time delay type 6 A 575 to 460 volt transformer is provided for these motors ELECTRICAL DATA UNITS WITHOUT EXHAUST AIR FANS 1 DSC Model Supply Air Blower Motor HP Exhaust Air Fan Motors 1 Phase Unit Ampacity Amps Max Fuse Size 2 Amps Min Wire Size 3...

Страница 11: ...g FF 1 1 2 Pipe 360 480 Drain Conn GG 2 5 8 KO 360 480 Gas Heat Piping1 HH 2 3 8 KO 360 Gas Heat Piping2 JJ 1 1 8 KO 360 480 Control Wiring KK 3 5 8 KO 480 Power Wiring LL 3 5 8 KO 360 Power Wiring 1 Heating Option G560 G800 2 Heating Option G400 DIM MODEL DSC 360 480 A 164 184 B 32 32 C 100 120 D 100 120 E 4 5 8 F 5 G 5 5 8 H 11 1 4 J 42 K 55 1 2 L 65 M 73 N 57 3 8 77 1 2 FRONT Control Box Side 3...

Страница 12: ... by the unit is absorbed in the chamber and not transmitted to the condi tioned space The chamber may be constructed of fiberglass duct or metal duct lined with sound absorption material Ceiling return grilles should be located a minimum of 12 feet from the end of the sound chamber In every installation a return air duct must be installed to the unit FILTERS All filters being used in these units a...

Страница 13: ...tside and return air dampers should be checked to make sure they operate freely and close tightly It may be necessary to readjust the linkage between the damper motor and the blades due to loosening in shipment Readjust linkage as follows 1 Turn the minimum outside air adjuster to the 100 outside air position All return air damper blades should be fully closed Be sure that the spring return damper...

Страница 14: ...oses in the compressor control circuit NOTE The above operation is for intermittent fan operation For continuous operation the fan switch on the room thermostat or the status panel should be manually closed to energize 7R 6 Relay contact 1R closes and energizes 1M coil which starts the No 1 compressor At the same time 4M coil is energized to start the condenser fans 7 If the room temperature conti...

Страница 15: ...ll not allow outdoor air to enter the unit during high humidity conditions except at a lower outdoor temperature During dry conditions air is introduced at a higher ambient The outdoor and return air dampers are controlled by the logic panel The discharge sensor acts as a modulating low limit which senses the temperature of the air leaving the evaporator coil If at any time during the cooling cycl...

Страница 16: ...he compressor un loading solenoid which loads the compressor 9 The compressor short cycle time and low voltage protection is part of the solid state compressor protection module It prevents a compressor from starting unless it has been off for five minutes It also monitors the voltage of the 120 volt control circuit and will shut down the compressor if the 120 volt control voltage drops below 85 æ...

Страница 17: ...erence line The recommended deflection force is as follows e Tension new belts at the maximum deflection force recommended for the belt section Check the belt ten sion at lease two times during the first 24 hours of operation Any retensioning should fall between the minimum and maximum deflection force values f After adjusting retighten nuts A 5 All pulleys are factory aligned 6 All supply air mot...

Страница 18: ...f operation check all belts and pulleys for tightness and align ment WARNING Failure to properly adjust the total system CFM can result in extensive blower damage FIG 17 HOLE LOCATIONS FOR SUPPLY AIR CFM CHECK FIG 18 PRESSURE DROP ACROSS A DRY EVAPORATOR COIL VS SUPPLY AIR CFM MODEL OF NOMINAL CFM 80 90 100 110 120 CFM DSC360 9600 10800 12000 13200 14400 DSC480 12800 14400 16000 17600 19200 MASTER...

Страница 19: ...Off On On Fan Compr 1 On O S A dampers operate to setting of mixed air control Compr 1st Stage Cool Off St 1 Cpr Auto On Off Off Off On Off Off On Fan Compr 1 On with O S A dampers open to min position Compr 2nd Stage Cool Off St 1 St 2 Cpr Auto On Off Off Off On On Off On Fan Compr 1 2 run with O S A dampers open to min position Heat 1st Stage Heat St 1 Off Auto On Off On Off Off Off Off On Heat ...

Страница 20: ...FIG 19 FIXED OUTDOOR AIR ADJUSTMENT FIG 20 EXHAUST AIR PERFORMANCE 530 25 N3Y 20 Unitary Products Group ...

Страница 21: ...haust Air 022 028 035 042 050 Return Air Damper for Economizer End Duct Connection 179 226 279 338 402 Return Air Damper for Economizer Side by Side Btm Duct 077 097 120 145 173 2 30 Efficient Filters1 007 009 011 014 016 Bag Type Filters1 056 071 089 107 127 End Duct Connections2 143 181 224 271 323 480 12800 14400 16000 17600 19200 G560 Gas Heat 038 049 06 073 086 G800 Gas Heat 051 065 08 097 11...

Страница 22: ...W SP BHP KW SP BHP KW SP BHP KW 900 1 12 8 84 7 55 0 75 10 11 8 76 0 30 11 59 10 03 950 1 42 9 73 8 44 1 05 11 17 9 66 0 60 12 73 11 02 1000 1 72 10 59 9 16 1 36 12 19 10 55 0 92 13 78 11 96 0 42 15 45 13 49 1050 2 00 11 50 9 95 1 66 13 16 11 40 1 23 14 78 12 86 0 76 16 56 14 53 0 21 18 45 16 23 1100 2 30 12 27 10 62 1 98 14 10 12 24 1 58 15 83 13 84 1 10 17 61 15 49 0 55 19 54 17 28 1150 2 62 13 ...

Страница 23: ... 1Mand 2M If however a low or high pressure cutout opens the lockout relay 10R or 11R will be energized Since the voltage across 10R or 11R will exceed 100V the voltage across 1M or 2M will be too low to pull in the contactors The normally closed contacts of 10R or 11R will open the circuit in series with the low or high pressure cutout When these contacts automatically close the lockout circuit c...

Страница 24: ... Check the compressor amps with the unit data plate 8 After approximately 15 minutes of operation check the liquid line sight glasses for a proper liquid refrigerant seal in each of the refrigerant circuit s 9 Next increase the setting of the room thermostat until the heating contacts are energized 10 Refer to the proper heating installation and operation instruction for the correct heating sequen...

Страница 25: ...After the unit is functioning properly instruct the owner and operator on how to operate the unit Replace all panels before leaving the job site 530 25 N3Y Unitary Products Group 25 ...

Отзывы: