Dunham-Bush MM0305F, MM0307A Installation, Operation & Maintanance Manual

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Page 1

INSTALLATION,

Form No.: MM0305F/MM0307A

OPERATION &

MAINTENANCE

MANUAL

Products That Perform...By People Who Care

ACCS

HEB-D

Air - Cooled Split System

Air Conditioner

with Scroll

Compressors

R22 / R407C

VEB-D

COOLING

HEAT PUMP

Page 2

TABLE OF CONTENTS

DESCRIPTION PAGE NO

1.0 INTRODUCTION.............................................................................................................................................3

1.1 NOMENCLATURE.................................................................................................................................. 3

2.0 GENERAL INFORMATION

2.1 RECEIVING, INSPECTION AND PACKAGING .....................................................................................4

2.1.1 Air-Cooled Condensing Units ( ACCS ) ....................................................................................... 4

2.1.2 Evaporator Blower Units ( HEB/VEB/EB )....................................................................................4

2.2 RIGGING AND UNCRATING .................................................................................................................4

2.3 LIMITATIONS.........................................................................................................................................4

3.0 INSTALLATION

3.1 CONDENSING UNITS INSTALLATION.................................................................................................5

3.2 AIR COOLED CONDENSING UNITS CLEARANCE..............................................................................6

3.3 EVAPORATOR BLOWER UNITS INSTALLATION................................................................................ 8

3.3.1 Typical VEB / EB Ducting System.............................................................................................. 8

3.3.2 Typical HEB Ducting System..................................................................................................... 8

3.4 EVAPORATOR BLOWER UNITS CLEARANCE....................................................................................9

3.4.1 Vertical Casing Type – VEB, EB................................................................................................9

3.4.2 Horizontal Casing Type – HEB ................................................................................................ 10

3.5 DUCT CONNECTION........................................................................................................................... 11

3.6 FIELD PIPING ...................................................................................................................................... 11

3.7 REFRIGERANT PIPING....................................................................................................................... 13

3.8 LEAK TEST ( SYSTEM PRESSURE TEST )........................................................................................ 14

3.9 VACUUM TEST AND DEHYDRATION................................................................................................. 14

3.10 INSTALLATION OF DRIERS OR SIGHT GLASS................................................................................. 15

3.11 CHARGING .......................................................................................................................................... 15

3.12 LUBRICATION...................................................................................................................................... 15

3.13 SENSING BULB LOCATION................................................................................................................ 15

3.14 EXTERNAL EQUALIZER CONNECTION............................................................................................. 16

3.15 HOT GAS BYPASS .............................................................................................................................. 16

3.16 TIGHTENING OF PULLEY SET SCREW............................................................................................. 17

3.17 PULLEY ALIGNMENT.......................................................................................................................... 17

3.18 BELT TENSION INSPECTION GUIDE................................................................................................. 17

4.0 OPERATION

4.1 PHASE ROTATION.............................................................................................................................. 18

4.2 CYCLE LIMIT RATE............................................................................................................................. 18

4.3 FAN CYCLING (OPTIONAL, STANDARD FOR HEAT PUMP)............................................................ 18

4.4 DEFROST CYCLE (STANDARD FOR HEAT PUMP) .......................................................................... 18

4.5 CRANKCASE HEATER (HEAT PUMP)................................................................................................ 18

4.6 STOP VALVE ....................................................................................................................................... 18

4.7 HYDROPHILIC CONDENSER COIL (STANDARD FOR HEAT PUMP)............................................... 18

4.8 STAINLESS STEEL BOLTS AND NUTS .............................................................................................. 18

4.9 DIMENSIONAL DATA........................................................................................................................... 19

4.10 TYPICAL OPERATING SEQUENCE.................................................................................................... 24

5.0 MAINTENANCE

5.1 MAINTENANCE.................................................................................................................................... 25

5.2 TROUBLE SHOOTING CHART ........................................................................................................... 26

5.3 SAMPLE LOG SHEET.......................................................................................................................... 29

Page 3

1.0 INTRODUCTION

The Dunham-Bush air-cooled split system air conditioner and heat-pumps are designed, matched, manufactured tested and ready for installation when it reached the site. The evaporator unit consists mainly of a direct expansion evaporator coil(s) with factory package thermal expansion valve, to be coupled with air cooled condenser unit consisting of scroll compressor(s) and large heat rejection condenser coil with integral subcooling circuit(s). Factory standard units also incorporate important safety and operating controls which includes manual reset high and low pressure cutout and compressor motor protectors for each compressor(s).

Every Dunham-Bush air-cooled split air-conditioner and heat pumps have been subject to stringent quality control and accurately testing as a final verification of reliability. If it is correctly installed, operated and maintained, it will provide many years of satisfactory and efficient performance.

Note: These instructions are general in nature and are for standard

units only. Non-standard units may vary in some respects from these instructions to suit particular applications.

1.1 NOMENCLATURE

ACC S 445 Q P

Air Cooled Condensing

S - Scroll Compressor

Model Code

EB 445 D Q P

VEB/ EB - Vertical

HEB - Horizontal Evaporator

Model Code

Evaporator Blower

Blower

Generation

Blank - R22 P - R407c

Blank - Standard Q - Special

Blank - R22 P - R407c

Blank - Standard FB - Free Blow Q - Special

Page 4

2.0 GENERAL INFORMATION

2.1 RECEIVING, INSPECTION AND PACKAGING

As soon as the unit is received, it should be inspected if there is any damage during transit. Make a separate written request if there is any damage on the carrier's delivery order. Also, the unit should be inspected for any missing or short shipped components. Standard items and accessories that come with the unit are:

2.1.1 AIR-COOLED CONDENSING

UNITS (ACCS)

1.) Compressor(s) c/w rubber grommet.

2.) Condenser coil(s).

3.) Condenser fan(s)- Refer to physical

data for sizes and quantity.

4.) Condensers fan motor(s)- Refer to

physical data for horsepower and quantity.

5.) Fan grille.

6.) High and Low pressure switch.

7.) Reversing valve, check valve

suction accumulator and compressor crankcase heater (standard for heat pump only).

8.) Optional accessories (if any).

1. IEC-DOL (Direct On Line) starter, wired

2. Low ambient fan cycling (standard for Heat-Pump).

3. Hot gas bypass

4. Stop valves

5. Mains isolator

6. Hydrophilic condenser coil fins (standard for Heat Pump)

7. Indicator lights

8. Stainless steel bolts and nuts

2.1.2 EVAPORATOR BLOWER UNITS (HEB-D/ VEB-D/ EB-D)

1.) Blower(s) wheel.

2.) Evaporator coil.

3.) Thermal expansion valve(s) and

distributor(s).

4.) Bearings and shaft.

5.) Optional accessories.

1. Double wall casing

2. Hot water heating coil

3. Electric heater coil

4. Thermostat, unit mounted for cooling only

5. Thermostat, remotely mounted for cooling only and heat pump

6. Discharge plenum and return air grille

2.2 RIGGING AND UNCRATING

Each unit has been tested, inspected and properly packed or crated prior to delivery. It is very important that precaution is taken in handing the units by the installers, movers and riggers. When lifting with slings, use spreader bars across the top of the unit to prevent any damage to the frame and panels. Rigging should be done in a manner to avoid any severe strain or stress on the unit which will scratch the paint works and damage the panels and framework. Avoid possible surface damage by not removing the packaging material until the unit is at or near the final location and soon to be installed. Check the weight of the unit before rigging. Place the rigging cable such that the weight is evenly distributed.

2.3 LIMITATIONS

1.) Avoid low return air temperature on

evaporator coil which might cause condensate to freeze up the surface of the evaporator coil.

2.) Avoid moisture carry over and excessive

noise, limit evaporator coil face velocity to 3.05 m/s [600FPM].

3.) Unit must be operated on the correct

electrical supply as specified on unit nameplate. Voltage limitation for compressor(s) and fan motor must be observed.

4.) Avoid low return air temperature on the

condensing coil which might cause low discharge pressure (heat pump unit is equipped with fan cycling to maintain the head pressure). Refer to Table 2.3.

TABLE 2.3 LIMITATION

(AIR TEMPERATURE °F[°C])

DB WB

INDOOR MAX. 95 [35] 72 [22]

MIN. 66 [19] 57 [14]

OUTDOOR MAX. 115 [46] -

MIN. 66 [19] -

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3.0 INSTALLATION

3.1 CONDENSING UNITS INSTALLATION

In installing the condensing units, considerations should be given to the following:

1.) Installed outside the building or ensure

sufficient air to the condenser.

2.) Strong foundation to withstand the unit's

weight and vibration. If the base was not leveled, use concrete blocks as base. It is also suggestable to provide rubber or spring isolators to isolate the units vibration.

If installing two units together, make sure that the discharge air from one unit were not circuited by the other unit. (Figure

3.1.)

5.) Location where there is no direct heat

source such as near a generator. This is because if the entering air temperature is high, then the unit will operate at high condensing temperature and subsequently trip on high pressure (during cooling mode).

6.) Location where the unit is not exposed to oily area, salty atmosphere, and sulphide gaseous area.

3.) Sufficient space for wiring and maintenance as per local legislation.

4.) Location where air is allowed to circulate.

Note: Condenser fans are of the propeller

type and not suitable for use with ductwork.

FIGURE 3.1: INSTALLING TWO UNITS TOGETHER

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3.0 INSTALLATION

3.2 AIR-COOLED CONDENSING UNITS CLEARANCE

(SUGGESTED)

ACCS 68, 81, 95

ACCS 108, 125, 145

ACCS 160, 190, 220, 250, 290

ACCS 320, 380, 435

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3.0 INSTALLATION

ACCS 480, 510, 570

ACCS 640, 700, 760

ACCS 800, 890, 960

ACCS 1020, 1140, 1340, 1520

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3.0 INSTALLATION

3.3 EVAPORATOR BLOWER UNITS INSTALLATION

3.3.1 TYPICAL VEB-D / EB-D DUCTING SYSTEM

3.3.2 TYPICAL HEB-D DUCTING SYSTEM

Leave the unit in its packaging until it reaches the final destination. This unit is designed for indoor installation only. In installing the unit, these suggestions should be given consideration so that the unit will operate with optimum capacity and also to ease the installation and future services.

Page 9

3.0 INSTALLATION

1.) Location that can withstand the unit's weight.

a.) Sometimes it is necessary to reinforce the ceiling with crossbeam or framework. b.) Use suspension bolts to install the unit and make sure the bolts can withstand the weight

distribution.

2.) Location that minimize the drain piping and field piping distance.

3.) Location that minimize the ducting length.

4.) Location where there is

no direct heat and air is allowed to circulate.

5.) It is suggestable to place

the unit higher than the floor level, for ease of drain piping. The base should be 4” [100mm] higher and leveled. Fix the unit to the base with anchor bolts. It is also suggestable to place vibrating isolation component between the unit and the base.

6.) Check the levelness of

the ceiling using a level gauge.

3.4 EVAPORATOR BLOWER UNITS CLEARANCE

3.4.1. VERTICAL CASING TYPE- VEB, EB

a.) VEB 108D, 125D, 145D, 160D, 190D, 220D, 250D

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3.0 INSTALLATION

b.) EB 250D, 290D, 320D, 380D, 435D, 480D, 510D, 570D, 640D, 700D, 760D

c.) EB 800D, 890D, 960D, 1020D, 1140D, 1340D, 1520D.

3.4.2. HORIZONTAL CASING TYPE- HEB

HEB 68D, 81D, 95D, 108D, 125D, 145D, 160D, 190D, 220D

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3.0 INSTALLATION

3.5 DUCT CONNECTIONS

All ducts shall be made according to local and/ or national codes and also with good duct installation practice. Minimize static losses by limiting the number of bends.

Suspended duct work with flexible hangers shall not be fastened directly to the unit.

A length of straight duct shall be installed as per Figure 3.5. This is to ensure uniform flow of discharge air. If an elbow need to be installed, then it shall be 1.5 of equivalent duct diameter. (Equivalent duct Ø= (4ab/π)

0.5

Please refer to AMCA standard for proper ducting installation/ guidelines.

FIGURE 3.5: SUGGESTED METHOD FOR CONNECTING SUPPLY DUCT

Model A R

HEB/EB 68D – 125D 40”[1016mm] 25”[635mm] HEB/EB 160D – 760D 60”[1524mm] 35”[889mm] EB 800D – 1520D 80”[2032mm] 50”[1270mm]

Note: Transition element shall not be greater than 15° for converging elements nor greater 7° for diverging element.

3.6 FIELD PIPING

1.) COMPRESSOR (CONDENSING UNIT) IS ABOVE THE EVAPORATING UNIT.

Note: Traps should be provided for every 20 ft [6.1m] of vertical riser for proper oil movement.

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3.0 INSTALLATION

2.) EVAPORATING IS ABOVE THE COMPRESSOR.

Note : Traps should be provided for every 20ft [6.1m] of vertical riser for proper oil movement.

3a.) TYPICAL PIPING SCHEMATIC (WITH OPTIONAL ACCESSORY AS INDICAT ED)

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3.0 INSTALLATION

3b.) TYPICAL PIPING SCHEMATIC – HEAT PUMP (WITH OPTIONAL ACCESSORY

AS INDICATED)

3.7 REFRIGERANT PIPING

1.) Prior to connecting the tubes, make sure to

apply blind caps or water proof tape to prevent dust or water from getting into the tubes.

Model Max. Allowable

Piping Length (L)

ACCS 68-1520 75 ft 30 FT

2.) Horizontal discharge and suction lines

should be sloped in the direction of flow at a rate of 1” [25.4mm] for every 20ft [6.1m] in order to aid oil drainage. If there is a vertical riser of more than 5ft [1.5m] on the suction line, there should be a trap at the bottom. For long suction vertical riser, additional trap is recommended for each 20ft [6.1m] of riser to insure proper oil return.

3.) The suction and liquid line should be sized

according to the manufacturers standard.

4.) Minimize the exposure time to atmosphere

during brazing.

5.) Drain pipe size should be the same or

bigger than the existing pipe. The pipe should be installed in downward slope so that water is drained by gravity. A trap

Elevation Difference

Between Two Units

must be provided on the pipe so that condensate will drain and not overflowing the drain pan. In addition, upon start-up, the water will not be sucked by the blower. In addition, the evaporator coil is located before the intake of the centrifugal blowers and operates below atmospheric pressure. Thus, to compensate for this pressure differential, a trap is required.

6.) Suction line must be insulated to prevent condensation. It is also suggestable to insulate the liquid line. Insulating these line will prevent unnecessary heat losses/ gains.

7.) This unit is designed to run up to max pipe length (single distance) 75ft [22.9m]. For length exceeding 75ft [22.9m], consult factory for assistance (piping size need to be changed and oil need to be added.).

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3.0 INSTALLATION

3.8 LEAK TEST (SYSTEM PRESSURE TEST)

1.) Leak test pressure is at 200psig

[1380kPa]. Disconnect or shut off all devices which may be damaged by 200psig [1380 kPa] test pressure.

2.) Open all valves in system so that entire

system can be pressurized and connect refrigerant cylinder to charging connection.

3.) Charge in freon vapor to the system until

50psig [345 kPa] and then pressurize with dry nitrogen until 200psig [1380 kPa]. Stop charging gas if noise of escaping gas is heard. Skip to sequence (6.)

Caution: Always use inert gas such as nitrogen for testing. Never use other gases such as Oxygen or acetylene which may be inflammable.

4.) With pressure at 200psig [1380kPa], shut

off the valve connecting nitrogen cylinder to the system. Disconnect nitrogen cylinder and leave pressure gauge indicating 1380kPa connected to system.

5.) With halide torch or electronic leak

detector, leak check every valve, joint, pressure control, coils and headers. Mark every leak and record down as remarks.

6.) When all leaks have been found, blow off

charge through tube to outside to prevent refrigerant accumulation around the system.

7.) Repair all leaks (check off on your

remarks): If rebrazing is required, feed nitrogen through into the system at slightly excessive pressure (leave system open and make sure nitrogen flows through).

8.) After repairing leaks, re-check as per

procedure 1 through 7.

9.) When system tight after leak test, keep

pressurized at 200psig [1380kPa] and hold for 12 hours. Full in pressure should be negligible (some may be due to temperature change only.)

10.) When system is tight, proceed with vacuum test and dehydration.

3.9 VACUUM TEST AND

DEHYDRATION

The purpose of evacuation is to evacuate the system when it is known or suspected that the system has been exposed to atmosphere, and there is a possibility that moisture has entered the system.

1.) Blow-off charge or pump down the

refrigerant.

2.) Connect vacuum pump the liquid line

valve and carefully check the unit piping to ensure all passages are open. (NEVER USE SYSTEM COMPRESSOR TO EVACUATE).

3.) Start vacuum pump operation and pull

vacuum to about 2 to 2.5mmHg [0.26 to

0.33 kPa] absolute pressure. During evacuation the pressure may remain steady for sometime at about 0.5” or 12mmHg [1.69 kPa] absolute pressure. This is caused by moisture evaporating in the system. This "boiling off" or "evaporation period" last about the same period of time as it took from initial start to reach this point.

4.) When the "boiling off" period lasts longer

that indicated under 3, break vacuum with refrigerant or nitrogen gas to sweep moisture out and evacuate and dryer shells, etc., up to a temperature of 100°F [37.8°C].

5.) Break vacuum with refrigerant or nitrogen

gas until pressure is 0psig [0 kPa].

6.) Re-evacuate to 1mmHg [0.133kPa]

absolute pressure.

7.) Disconnect vacuum pump and leave

system standing for 6 hours. There should be no change in vacuum during this period. If there is a change repeat 1 to 7.

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3.0 INSTALLATION

3.10 INSTALLATION OF DRIERS OR SIGHT GLASS

1.) Break vacuum with nitrogen.

2.) When permanently brazed drier or sight

glass is used, open one valve on system to atmosphere while maintaining slight nitrogen flow.

3.) When flare connected drier or sight glass is

used, use similar procedure as under 2. However, no valve need to be left open to atmosphere.

4.) When replaceable dryer core is used follow

procedure as under 3. Insert drier core(s). Tighten cap screws.

5.) Re-evacuate system to 1mmHg [0.133

kPa] absolute.

3.11 CHARGING

1.) Connect refrigerant cylinder through

charging connection to charging valve.

2.) Loosen flare nut on other end of charging

connection and blow air out with refrigerant. Tighten flare nut on charging connection.

3.) Weight refrigerant cylinder.

4.) Open charging valve and charge in

refrigerant vapor through suction access valve until about 150psig [1034 kPa]. Switch to liquid line access valve and charge in liquid refrigerant. Continue charging with liquid refrigerant until clear glass is observed.

5.) Shut off refrigerant charging valve but

keep connected. Check charging valve flare nut for leak. Check and record down discharge and suction pressure. If more than one system to be charged, follow procedure 1 through 4 for each system. After all the systems have been done up to step 4, proceed with 5 and 6.

6.) Shut off the system (compressor, fans, pumps) and leave for 24 hours.

3.12 LUBRICATION

The scroll compressor use mineral oil 3GS, for R22 compressors and POE (Polyol ester) oil for HFC refrigerants (R134a, R407c etc) compressors. Please refer to compressor name plate for original oil charge. Recharge shall be 118ml less than the original charge. The condenser fan used a direct-drive permanent split capacitor motor. The motor should be lubricated with 30 to 40 drops of SAE #20 non-detergent oil as follows depending on service:

LIGHT DUTY -After 25,000 operating

hours.

NORMAL DUTY -Annually after three years

or 8,000 operating hours.

HEAVY DUTY -Annually after one year

or at least every 1500 operating hours.

CAUTION: DO NOT OVER OIL

3.13 SENSING BULB

LOCATION

1.) Sensing bulb is not installed for the evaporator unit due to limited space and for precautionary reasons.

2.) The sensing bulb should be attached to a horizontal suction line at the evaporator outlet.

3.) If more than one TXV is used on evaporator sections, make sure that the sensing bulb of each valve is applied to the suction line of the evaporator fed by that valve.

4.) On suction lines 7/8” [22.2mm] OD and larger, it is recommended that the bulb be installed at 4 or 8 o’clock on the side of the horizontal line and parallel with respect to the direction of flow. On smaller lines, the bulb should be mounted on the top of the line. See Figure 3.13.

Page 16

3.0 INSTALLATION

FIGURE 3.13: REMOTE BULB

1. Remote Bulb Small Suction Line (Smaller Than 7/8” [22.2mm])

2. Remote Bulb On large Suction Line (7/8” [22.2mm] and Larger)

5.) For good thermal contact, the bulb should be securely fastened with two bulb straps to a clean, straight section of the suction line. It should be insulated with cork tape to prevent the effect of surrounding environment.

3.14 EXTERNAL EQUALIZER

CONNECTION

The equalizer connection should be made at a point that will most accurately reflect the pressure existing in the suction line at the bulb location. Generally, the connection is as close to bulb on the downstream side.

3.15 HOT GAS BYPASS

The purpose of the hot gas by pass is to create artificial load in the system by means of injecting hot gas into the inlet of the distributor. This would prevent the suction pressure from falling below the desired settings and thus causing frequent compressor cycling. The valve is pressure actuated, where it allows the discharge gas to bypass if the downstream pressure is below the setting. The setting could be changed by adjusting the stem

on the valve body. To set the pressure, loose the seal nut as shown below and turn the adjusting stem clockwise to raise the pressure or counter clockwise to lower the pressure. One turn of the stem equals to 16psig [110.3kPa]. The adjustment range for the valve is between 10”Hg [33.8kPa] to 120psig [827 kPa].

It is important that the setting to be performed under actual operating condition, i.e. under minimal system load conditions so that it could maintain the minimum desired suction pressure. Hot gas flow could be detected by listening the gas flowing through the valve or by touching the outlet pipe.

Page 17

3.0 INSTALLATION

3.17 TIGHTENING OF

PULLEY SET SCREW

Apply one or two drops of thread locked 243 to the engagement area of set screws before tightening the pulleys according to the recommended torque.

Set Screw Size Tightening Torque

5/16” [7.9mm] 10 Lbs.ft [13NM]

3/8” [9.5mm] 19 Lbs.ft [26NM]

3.18 PULLEY ALIGNMENT

1.) Insert one end of the string inside the gap between belt and pulley.

2.) Rotate the pulley so that string is clipped between the pulley and the belt.

3.) Pull the other end of the string as per figure below.

FIGURE 3.17:

4.) Inspect for any gap between the string and pulley at A and B.

5.) If find any gap then adjust either pulley to make the gap as small as possible.

6.) Repeat steps 1, 2, 3, 4 and 5 for bottom of the same side, top and bottom of the other side. (As shown as Figure 3.17)

3.18 BELT TENSION

INSPECTION GUIDE

1.) Measure the belt span (See Figure 3.18).

2.) Position of the “O” ring on the span scale at the measure belt.

3.) Set the “O” ring on the deflection force scale to zero.

FIGURE 3.18: BELT SPAN

4.) Place the tension meter squarely on the belt at the belt span. Apply a force on the plunger and perpendicular to the belt span until the bottom of the “O” ring even the top of the next belt or with the bottom of a straight edge laid across the sheaves.

5.) Remove the tension meter and read the force applied from the bottom of the “O” ring on the deflection force scale.

6.) Compare the force you have applied with the values in Table 3.18a and 3.18b.

Note: A new drive should be tensioned to the higher value. After the drive has been running for 30 minutes, the tension should be checked and readjust to the higher value, if necessary.

Table 3.18a:

Belt Span Lt (cm) Deflection Td (cm)

25 – 30 31 – 36 37 – 42

43 – 48 49 – 54 55 – 60

61 – 66 67 – 72 55 – 60

79 – 84 85 – 90 91 – 96

97 – 102 103 – 108 109 - 114

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

Table 3.18b:

Belt

Type

Small Pulley Diameter –

inches [mm]

A 3.0 - 5.5 [76 – 140] 2.2 – 3.3 [1.0 - 1.5] B 5.0 - 8.0 [127 – 203] 4.4 – 6.8 [2.0 - 3.1] C 8.0 - 16.0 [203 – 406] 9.0 – 13.4 [4.1 - 6.1]

Maximum Deflection –

lbs [Kg]

Page 18

4.0 OPERATION

4.1 PHASE ROTATION

Avoid running in reverse rotation. If during initial start up the compressor does not build up pressure, noise is abnormally loud and power consumption is minimal, then there is a possibility that the unit is operating at reverse rotation. Shut down the power and connect phase to the proper terminals. Running reverse may damage the compressor (s).

4.2 CYCLE LIMIT RATE

Each compressors must not be cycle on-off for more than 12 times per hour. The higher number of starts per hour will reduce the life of the compressor. Thus, it is suggested that anti short cycle timer is provided in the system.

4.3 FAN CYCLING (OPTIONAL, STANDARD FOR HEAT PUMP)

During cooling only, the head pressure control would allow the unit to operate at lower ambient temperature by building up the discharge pressure through cycling of fans (for single fan unit, this is achievable by reducing the fan speed). If there is demand for cooling. The unit would run on cooling until the manual charge over is set to heating. Please observe the lowest ambient for cooling mode. For heat pump units fan cycling is standard.

4.4 DEFROST CYCLE (STANDARD FOR HEAT PUMP)

During heating, a defrost controller would initiate the defrost cycle once there is demand for it. The sensor from the controller would sense the suction pressure and if the pressure is lower then the preset value, Then a signal

would be sent to the control panel which then relay the signal to the reversing valve to reverse the cycle. Now, the outdoor coil would be discharging hot air and defrosting the ice on the fins surface. The standard factory set timer for the defrost cycle is 10 minutes which could be adjusted according to the site condition.

4.5 CRANKCASE HEATER (STANDARD FOR HEAT PUMP)

Refrigerant tend to migrate to colder section of the unit. During winter, the compressor compartment is at lower temperature than the evaporator and thus refrigerant tend to accumulate in the compressor compartment. Connect power source to the unit a few hours prior to compressor start up so that the refrigerant would be forced out of the compressor compartment. It is good practice to let the crankcase heater to be energized continuously, independent of compressor operation.

4.6 STOP VALVE

Inspect all stop valves prior to start up. They shall be in open position.

4.7 HYDROPHILIC CONDENSER COIL (STANDARD FOR HEAT PUMP)

Hydrophilic fins assist condensation to be removed faster and therefore reduced the possibility of icing on the coil.

4.8 STAINLESS STEEL BOLTS AND NUTS

Reduce the possibility of corrosion especially when the environment is corrosive.

Page 19

4.0 OPERATION

4.9 DIMENSIONAL DATA

1.) Air Cooled Condensing Units ACCS 68, 81, 95

ACCS 108, 125, 145

MODEL A B C D E

ACCS 68

46 1/2[1181] 42 11/16[1084] 14 3/8[365] 29 7/16[748] 15 3/4[400] 7/8[22] (1) 3/8[10] (1)

ACCS 81

48 1/2[1232] 44 3/8[1127] 19 5/16[491] 35 1/4[895] 20 7/8[530] 7/8[22] (1) 1/2[13] (1)

ACCS 95

48 1/2[1232] 44 3/8[1127] 19 5/16[491] 35 1/4[895] 20 7/8[530] 7/8[22] (1) 1/2[13] (1)

OTE: ACCS 68 IS WITH SERVICE VALVE.

MODEL

ACCS 108 ACCS 125 ACCS 145

1 3/8[35] (1) 1/2[13] (1) 1 3/8[35] (1) 1/2[13] (1) 1 3/8[35] (1) 5/8[16] (1)

SUCTION

SIZE

(QTY)

SUCTION

SIZE

(QTY)

LIQUID

SIZE

(QTY)

LIQUID

SIZE

(QTY)

ACCS 160, 190, 220, 250, 290

ACCS 160 ACCS 190 ACCS 220 ACCS 250 ACCS 290

NOTE : ALL DIMENSIONS ARE IN INCHES.

MODEL A

40 1/4[1016] 1 3/8[35] (1) 5/8[16] (1) 40 1/4[1016] 1 5/8[41] (1) 5/8[16] (1) 48 1/4[1219] 1 3/8[35] (1), 1 1/8[29] (1) 1/2[13] (2) 48 1/4[1219] 1 3/8[35] (2) 1/2[13] (2) 48 1/4[1219] 1 3/8[35] (2) 5/8[16] (2)

NOTE: ACCS 160 AND 190 ARE SINGLE COMPRESSOR

UNIT.

SUCTION SIZE

(QTY)

LIQUID

SIZE

(QTY)

Page 20

4.0 OPERATION

ACCS 320, 380, 435

ACCS 320 ACCS 380 ACCS 435

ACCS 480, 510, 570

ACCS 480 ACCS 510 ACCS 570

ACCS 640, 700, 760

NOTE : ALL DIMENSIONS ARE IN INCHES.

MODEL

A SUCTION

SIZE (QTY)

48[1219] 1 3/8[35] (2) 5/8[16] (2) 56[1422] 1 5/8[41] (2) 5/8[16] (2) 56[1422] 1 3/8[35] (3) 5/8[16] (3)

SUCTION SIZE (QTY) LIQUID SIZE

1 3/8[35] (3) 5/8[16] (3)

1 5/8[41] (1), 1 3/8[35] (2) 5/8[16] (3)

1 5/8[41] (3) 5/8[16] (3)

MODEL

ACCS 640 ACCS 700 ACCS 760

SUCTION SIZE (QTY) LIQUID

1 3/8[35] (4) 5/8[16] (4)

1 3/8[35] (2), 1 5/8[41] (2) 5/8[16] (4)

1 5/8[41] (4) 5/8[16] (4)

LIQUID SIZE

(QTY)

SIZE (QTY)

Page 21

4.0 OPERATION

ACCS 800, 890, 960

ACCS 1020, 1140, 1340, 1520

MODEL SUCTION SIZE

MODEL A SUCTION SIZE

ACCS 1020

ACCS 1140 ACCS 1340

ACCS 1520

ACCS 800

ACCS 890

ACCS 960

143[3632] 1 5/8[41] (2)

143[3632] 2 1/8[54] (3) 7/8]22] (3) 150[3810] 1 5/8[41] (3)

150[3810] 2 1/8[54] (4) 7/8[22] (4)

(QTY)

1 3/8[35] (5) 5/8[16] (5)

1 3/8[35] (2),

1 5/8[41] (3) 1 5/8[41] (3) 7/8[22] (3)

(QTY)

2 1/8[54] (1)

LIQUID SIZE

(QTY)

5/8[16] (5)

LIQUID SIZE

(QTY)

7/8[22] (3)

7/8[22] (4)

NOTE: ALL DIMENSIONS ARE IN INCHES.

Page 22

4.0 OPERATION

Evaporator Units

HEB 68D, 81D, 95D

HEB 68D HEB 81D HEB 95D

MODEL

HEB 108D, 125D, 145D, 160D, 190D, 220D

HEB 108D HEB 125D HEB 145D HEB 160D HEB 190D HEB 220D

MODEL

EB 250D, 290D, 320D, 380D, 435D

EB 250D EB 290D EB 320D EB 380D EB 435D

NOTES. : 1.) ALL DIMENSIONS ARE IN INCHES.

2.) UNITS SHOWN ARE RIGHT HAND PIPING CONNECTION.

A B C D E F

20[508] 46[1168] 24[610] 13[330] 11 3/8[289] 16 1/2[419] 20[508] 46[1168] 24[610] 13[330] 11 3/8[289] 16 1/2[419] 23[584] 46[1168] 30[762] 15 1/2[394] 13 1/2[343] 15 1/4[387]

27[686] 50[1270] 33[838] 15 1/2[394] 13 1/2[343] 21 1/4[540] 27[686] 50[1270] 33[838] 15 1/2[394] 13 1/2[343] 21 1/4[540] 27[686] 50[1270] 33[838] 15 1/2[394] 13 1/2[343] 21 1/4[540] 29[737] 58[1448] 40[1016] 18 1/2[470] 16[406] 24 3/8[619] 29[737] 58[1448] 40[1016] 18 1/2[470] 16[406] 24 3/8[619] 29[737] 78[1981] 40[1016] 18 1/2[470] 16[406] 30[762]

MODEL

A B C D E F

29[ 78 40 18 1/2 16 30

38 84 45 17 19 33 1/2 38 84 45 17 19 33 1/2 48 84 45 22 19 37 48 84 45 22 1/2 22 1/2 37

Page 23

4.0 OPERATION

EB 480D, 510D, 570D, 640D, 700D, 760D

EB 480D EB 510D EB 570D EB 640D

EB 700D EB 760D

EB 800D, 890D, 960D, 1020D, 1140D, 1340D, 1520D

VEB 108D, 125D, 145D, 160D, 190D, 220D, 250D

VEB 125D VEB 145D VEB 160D VEB 190D VEB 220D VEB 250D

NOTES. : 1.) ALL DIMENSIONS ARE IN INCHES.

2.) UNITS SHOWN ARE RIGHT HAND PIPING CONNECTION.

Model A B C D E F G H

VEB 108D

MODEL A B C D E F

51 1/2[1308] 52 [1321] 25[635] 15 1/2[394] 13 1/2[343] 17 1/4[438] 25 3/4[654] 25 3/4[654]

51 1/2[1308] 52[1321] 25[635] 15 1/2[394] 13 1/2[343] 17 1/4[438] 25 3/4[654] 25 3/4[654] 51 1/2[1308] 52[1321] 25[635] 15 1/2[394] 13 1/2[343] 17 1/4[438] 25 3/4[654] 25 3/4[654] 57 1/2[1461] 58 1/2[1486] 28[711] 18 5/8[473] 16[406] 15[381] 28 3/4[730] 28 3/4[730] 57 1/2[1461] 58 1/2[1486] 28[711] 18 5/8[473] 16[406] 15[381] 28 3/4[730] 28 3/4[730] 57 1/2[1461] 68[1727] 28[711] 15 1/2[394] 16[406] 26[660] 28 3/4[730] 28 3/4[730] 57 1/2[1461] 68[1727] 28[711] 18 1/2[470] 16[406] 24 3/4[629] 28 3/4[730] 28 3/4[730]

68[1727] 84[2134] 66[1676] 25[635] 25[635] 34[864] 68[1727] 84[2134] 66[1676] 25[635] 25[635] 34[864] 68[1727] 84[2134] 66[1676] 25[635] 25[635] 34[864] 78[1981] 84[2134] 66[1676] 28[711] 28[711] 34[864]

78[1981] 84[2134] 66[1676] 28[711] 28[711] 34[864] 78[1981] 84[2134] 66[1676] 28[711] 28[711] 34[864]

MODEL A B C D

EB 800D

EB 890D

EB 960D

EB 1020D

EB 1140D

EB 1340D

EB 1520D

[2489]

118

[2997]

118

[2997]

[2032]

[2184]

[1575]

[1778]

31 1/2

[800]

31 1/2

[800]

31 1/2

[800]

35 1/2

[902]

35 1/2

[902]

[1016]

31 1/2

[800]

31 1/2

[800]

31 1/2

[800]

35 1/2

[902]

35 1/2

[902]

[1016]

F G

[991]

[432]

[991]

[432]

[991]

[432]

[991]

[356]

[991]

[356]

[991]

[356]

[991]

[356]

Page 24

4.0 OPERATION

4.10 TYPICAL OPERATING SEQUENCE

Page 25

5.0 MAINTENANCE

5.1 MAINTENANCE

These units are designed to provide years of services with minimum maintenance. Nonetheless, it is a good practice to carry out

ITEM MAINTENANCE PROCEDURE RECOMMENDED SCHEDULE

regular inspection and checking to ensure the unit's optimum performance and compliance with local rules and regulations.

Air Filters 1. Washable type.

2. Clean with a vacuum cleaner or tapped lightly and then wash in luke warm water (below 104°F [40°C]).

3. Make sure the filter is dry.

Belt 1. Check the tension and alignment.

2. Move the motor if the belt is loose.

Pulley 1. Make sure the set screws are properly

tightened and there is no crack on the pulley.

Blower 1. Turn the blower manually. It should run

smoothly and there is no excessive bearing noise.

Bearing and Shaft 1. Check for evidence of wear. Once a year.

Bolts, Screws and Nuts.

1. Tighten any loose components. Once a year.

Once a month or depending upon the condition of the circulated air.

Once every six months.

Coil 1. Check and remove clogged item

between fins.

Paint 1. Check any evidence of corrosion. Once a year.

Compressor 1. Check if there is any leakage. Every six months.

Electrical 1. Check voltage, current and wiring.

2. Check connections.

Drain Pan and Pipe 1. Pour some water into the drain pan

and let the water run through. If the pipe is clogged, remove the dirt.

Once a year.

Every two months.

Every six months.

Page 26

5.0 MAINTENANCE

5.2 TROUBLE SHOOTING CHART

Page 27

5.0 MAINTENANCE

Page 28

5.0 MAINTENANCE

Page 29

5.0 MAINTENANCE

5.3 SAMPLE LOG SHEET SHEET NO..............................

DUNHAM-BUSH AIR COOLED SPLIT UNIT

UNIT MODEL NO. ........................................................UNIT NO..................................... VOLTS:.........................Hz.....................

UNIT SERIAL NO. ....................................................................................................................

START UP : DATE ..........................................TIME...................................................

DATE TIME

COMP. NO.

SUCTION PRESSURE

SUCTION TEMPERATURE

DISCHARGE PRESSURE

DISCHARGE TEMPERATURE

DISCHARGE SUPERHEAT (DISC. TEMP.-SAT. DISCH.)

SUCTION SUPERHEAT (SAT. SUCT .- SUC. TEMP)

RETURN AIR TEMPERATURE – DB/WB SUPPLY AIR TEMPERATURE – DB/WB AIR VOLUME AMBIENT AIR TEMPERATURE OFF CONDENSER AIR TEMPERATURE

COMPRESSOR AMPS

CONDENSER FAN AMPS EVAPORATOR FAN AMPS VOLTS

This log sheet is provided as a recommendation of the readings that should be taken on a periodic basis. The actual readings taken and the frequency will depend upon the units application, hours of use, etc. This type of information can prove very useful in preventing and/ or solving problems that might occur during the life of the unit.

Lot 5755-6, Kidamai Industrial Park, Bukit Angkat, 43000 Kajang, Selangor Darul Ehsan, Malaysia