Bohn ADT130BHB2N2K Installation Manual

H-IM-711C6

Part #25006501

(Replaces H-IM-711C5, 9/02)

December, 2003

INSTALLATION & OPERATING

INSTRUCTIONS

MCCU Condensing Units

TABLE of CONTENTS

General Safety Information ..................................2

Condensing Unit Specifications...........................2

Evaporator Specifications ....................................3

Evaporator Placement..........................................4

Condensing Unit Placement ................................. 5

Condensing Unit Rigging .....................................6

Refrigeration Piping and Line Sizing ...................7

Refrigeration Piping........................................ 8-10

Leak Detection and Evacuation ......................... 11

Field Wiring ................................................... 12-13

Beacon II Controller...................................... 14-26

Refrigeration Charging .......................................27

Operational Check-Out.......................................28

System Balancing ...............................................28

Preventive Maintenance............................... 29-31

Diagnostics.................................................... 32-35

Parts ....................................................................36

Wiring Diagrams ........................................... 37-42

Start-up Checklist ......................................... 43-44

™

General Safety Information

1. Installation and maintenance to be performed only by certified personnel who are familiar with this type of equipment.

2. Make sure that all field wiring conforms to the requirements of the equipment and all applicable national and local codes.

3. Avoid contact with sharp edges and coil surfaces. They are a potential injury hazard.

4. Make sure all power sources are disconnected before any service work is done on units.

Inspection

Responsibility should be assigned to a dependable individual at the job site to receive material. Each shipment should be carefully checked against the bill of lading. The shipping receipt should not be signed until all items listed on the bill of lading have been accounted for. Check carefully for concealed damage. Any shortage or damages should be reported to the delivering carrier. Damaged material becomes the delivering carrier’s responsibility and should not be returned to the manufacturer unless prior approval is given to do so. When uncrating, care should be taken to prevent damage. Heavy equipment should be left on its shipping base until it has been moved to the final location.

Condensing Unit Specifications

Figure 1.

Table 1. Condensing Unit Specification Data

Condensing Unit Unit Unit

Model Compressor Location Voltage HP Ref. MCA MOP

CRN5-500 Cooler 208/230/3/60 5 22

MCCU56049B2N KALA-016E Freezer 208/230/3/60 1.5 404A 45 60

RS55C1E Ice Storage 208/230/1/60 1.0 404A

CR37KQ Cooler 208-230/3/60 3.0 22

MCCUCSTORE3B2N KALA-016E Freezer 208-230/3/60 1.5 404A 35 40

KALB-010E Ice Merch. 208-230/1/60 1.0 404A

CR53KQ Cooler 208-230/3/60 4.0 22

MCCUCSTORE4B2N KALA-016E Freezer 208-230/3/60 1.5 404A 43 50

KALB-010E Ice Merch. 208-230/1/60 1.0 404A CRN5-0500 Cooler 208-230/3/60 5.0 22

MCCUCSTORE5B2N KALA-016E Freezer 208-230/3/60 1.5 404A 46 60

KALB-010E Ice Merch. 208-230/1/60 1.0 404A

MCA = Minimum Circuit Ampacity MOP = Maximum Overcurrent Protection

Evaporator Specifications

Table 2. Evaporator Specification Data

Dimensions (in.) Connections Amps WEIGHT

Evaporator Model Location Fig Capacity

BTUH

ADT208BHB2N2K Cooler 2 20,800 77.50 65.25 --- --- 1 1/8 1/2 2.0 -- 82

TL53SB2N Freezer 3 5,300 46.50 --- 49.13 16.50 7/8 1/2 1.5 8.50 53

LET047BHB2N6K Ice Storage 2 4,700 29.50 17.25 --- --- 5/8 1/2 0.5 3.9 29

ADT130BHB2N2K Cooler 2 13,000 45.50 33.25 --- --- 7/8 1/2 1.0 -- 53

ADT156BHB2N2K Cooler 2 15,600 61.50 49.25 --- --- 7/8 1/2 1.5 -- 67

ADT208BHB2N2K Cooler 2 20,800 77.50 65.25 --- --- 1 1/8 1/2 2.0 -- 82

Figure 2.

A B W D Suct OD Liq. OD Mtrs. Htrs. (lbs.)

Figure 3.

Evaporator Placement

Typical Layouts for Illustration

(refer to build plans for actual room layout and equipment location)

The ADT/LET units are draw through units. For best operation, they should be located away from entry

doors and at least 18” from the wall with the fans blowing into the room. Make sure the units are flush

mounted to the ceiling to insure proper drainage for defrost water.

Figure 3. Evaporator Placement In Cooler/Freezer

H = Total

1 1/2 H

1 H

1 1/2 H

height of unit coil surface.

1 1/2 H

3 H

1 1/2 H

NOTE:

Always avoid placement of Unit Coolers directly above doors and door openings where low temperature is being maintained and wherever possible for medium temperature.

Whenever possible, always try to position the evaporator to blow towards the vault door. Never position it over or adjacent to a door opening.

Elevation view of glass display door cooler or freezer. Be sure air discharge blows above, not directly at doors. Provide baffle if door extends above blower level.

Condensing Unit Placement

Space and Location Requirements

The most important consideration which must be taken into account when deciding upon the location of aircooled equipment is the provision for a supply of ambient air to the condenser, and removal of heated air from the condensing unit or remote condenser area. Where this essential requirement is not adhered to, it will result in higher head pressures, which cause poor operation and potential failure of equipment. Units must not be located in the vicinity of steam, hot air or fume exhausts. Corrosive atmospheres require custom designed condensers.

Another consideration which must be taken is that the unit should be mounted away from noise sensitive spaces and must have adequate support to avoid vibration and noise transmission into the building. Units should be mounted over corridors, utility areas, rest rooms and other auxiliary areas where high levels of sound are not an important factor. Sound and structural consultants should be retained for recommendations. (Refer to actual building plans for unit locations.)

Figure 4. Condensing Unit Placement



3 Feet

(minimum)

Clearance to

3 Feet from

Building

Wall



the Next Unit



3 Feet

(minimum) Clearance

from MCCU to

an Open Block

Wall or

Shrubs.



3 Feet

(minimum)

Clearance for

Contractor to Service Unit.

Condensing Unit Rigging

Figure 5. Condensing Unit Rigging

Adequate rigging measures must be taken to support unit weight and to protect the unit from damage during unloading and placement process.

Rigging holes have been provided in legs and under the unit compressor compartment frame to assist.

Spreader bars may be used to protect unit from damage.

Refer to the

building plans

for construction

details.

Top of Roof

Roof Opening

Flashed and

Sealed

Rigging Holes

Disconnect

Curb

Refer to the

building plans

for construction

details.

Refrigeration Piping And Line Sizing

The system as supplied by Heatcraft, was thoroughly cleaned and dehydrated at the factory . Foreign matter may enter the system by way of the evaporator to condensing unit piping. Therefore, care must be used during installation of the piping to prevent entrance of foreign matter. Install all refrigeration system components in accordance with applicable local and national codes and in conformance with good practice required for the proper operation of the system. The refrigerant pipe size should be selected from the tables in Refrigeration System Installation Manual, Part Number 25001201. The interconnecting pipe size is not necessarily the same size as the stub-out on the condensing unit or the evaporator.

The following procedures should be followed: (a) Do not leave dehydrated compressors or filter-driers on condensing units open to the atmosphere any longer

than is absolutely necessary . (b) Use only refrigeration grade (ACR) copper tubing, properly sealed against contamination. (c) Suction lines should slope 1/4” per 10 feet towards the compressor (in direction of flow). (d) Suitable P-type oil traps should be located at the base of each suction riser to enhance oil return to the

compressor. (e) For desired method of superheat measurement, a pressure tap should be installed in each evaporator

suction line in the proximity of the expansion valve bulb. (f) When brazing refrigerant lines, an inert gas should be passed through the line at low pressure to prevent

scaling and oxidation inside the tubing. Dry nitrogen is preferred. (g) Use only a suitable silver solder alloy on suction and liquid lines. (h) Limit the soldering paste of flux to the minimum required to prevent contamination of the solder joint internally .

Flux only the male portion of the connection, never the female. After brazing, remove excess flux. (i) Remove temperature sensor attached to suction line on Beacon II systems before brazing of the solder joint

internally . Flux only the male portion of the connection – never the female. After brazing, remove excess flux. (j) Wrap expansion valves with wet rags during brazing to the liquid line.

CAUTION: If the temperature gets too high, these components may be damaged. Heat absorbing

compounds or wet rags must be used to protect the expansion valve when brazing to the refrigerant

piping/line connections, and the suction line sensor must be removed per above instructions.

(k) Do not use “bull head” tees. This will cause oil return problems and can cause poor performance. (l) If isolation valves are installed at the evaporator, full port ball valves should be used.

Figure 6. Refrigeration Piping Diagrams

SLOPE DOWN TO UNIT

PITCH AWAY FROM UNIT

1/2” LIQUID LINE

1-1/8” SUCTION LINE

7/8”

BEACON

ELECTRIC

EXPANSION

VALVE (TYP.)

FACTORY

MOUNTED

7/8”

3/8”

PIPING DIAGRAM FOR THE

(R22) MEDIUM TEMPERATURE COOLER

REFRIGERATION SYSTEM

10 DOOR VAULT COOLER

NOT TO SCALE

ROOF PENETRATION BY OTHERS

(SEE ARCH. PLANS)

1/2” LIQUID LINE

1/2” L

1-1/8” SUCTION LINE

INSULATED WITH 3/4”

WALL ARMAFLEX OR EQUAL

TO MCCU

UNIT ON ROOF

BRACE DOWN EVERY 6.0 FT.

PITCH DOWN

TOWARD UNIT

SLOPE DOWN TO UNIT PITCH AWAY FROM UNIT 3/8” LIQUID LINE

SUCTION LINE

BEACON

ELECTRIC

EXPANSION

VALVE

(TYP.) FACTORY MOUNTED

(R404a) LOW TEMPERATURE FREEZER

VAULT ICE MERCHANDISER

1/2”

3/8”

PIPING DIAGRAM FOR THE

REFRIGERATION SYSTEM

NOT TO SCALE

ROOF PENETRATION BY OTHERS

INSULATED WITH 3/4”

WALL ARMAFLEX OR EQUAL

UNIT ON ROOF

BRACE DOWN EVERY 6.0 FT.

PITCH DOWN

TOWARD UNIT

(SEE ARCH. PLANS)

3/8” LIQUID LINE

1/2” SUCTION LINE

TO MCCU

SLOPE DOWN TO UNIT PITCH AWAY FROM UNIT

3/8” LIQUID LINE

SUCTION LINE

ROOF PENETRATION BY OTHERS

BEACON

ELECTRIC

EXPANSION

VALVE

(TYP.) FACTORY MOUNTED

(R404a) LOW TEMPERATURE FREEZER

-10° VAULT STORAGE FREEZER

5/8”

3/8”

PIPING DIAGRAM FOR THE

REFRIGERATION SYSTEM

NOT TO SCALE

TO MCCU

UNIT ON ROOF

BRACE DOWN EVERY 6.0 FT.

PITCH DOWN

TOWARD UNIT

(SEE ARCH. PLANS)

3/8” LIQUID LINE

5/8” SUCTION LINE

INSULATED WITH 3/4”

WALL ARMAFLEX OR EQUAL

Refrigeration Piping

Suction Lines

NOTE: If the suction line must rise to the point higher than the suction connection on

the evaporator, a suction line trap at the outlet of the evaporator must be provided.

Horizontal suction lines should slope away from the evaporator toward the compressor at the rate of 1/4’ per 10 feet for good oil return. When multiple evaporators are connected in series using a common suction line, the branch suction lines must enter the top of the common suction line.

Suction lines that are outside of refrigerated space must be insulated. See “Line Insulation” for more information.

Suction Line Risers

NOTE: To provide proper oil return, a suction trap must be provided at the base of

all suction risers.

Prefabricated wrought copper traps are available, or a trap can be made by using two street ells and one regular ell. The suction trap must be the same size as the suction line. For long vertical risers, additional traps may be necessary. Generally, one trap is recommended for each length of pipe (approximately 20 feet) to insure proper oil movement. See Figure 7 below for methods of constructing proper suction line P-traps.

Figure 7. Suction P-traps

Condensate Drain Lines

Copper drain lines should be used and properly protected from freezing. In running drain lines, provide a minimum of 4 inches per foot pitch for proper drainage. Drain lines should be at least as large as the evaporator drain connection. All plumbing connections should be made in accordance with local plumbing codes. All condensate drain lines must be trapped, and run to an open drain. They must never be connected directly to the sewer systems. Traps in the drain line must be located in a warm ambient. We recommend a trap on all evaporators. Traps located outside, or extensive outside runs of drain line must be wrapped with a drain line heater. The heater should be connected so that it is continuously on. It is recommended that the drain line be insulated to prevent heat loss. A heat input of 20 watts per lineal foot of drain line for 0ºF (-18°C) room applications and 30 watts per lineal foot for -20°F (-29°C) rooms is satisfactory.

Inspect the drain pan periodically to insure free drainage of condensate. If the drain pan contains standing water, check for proper installation. The drain pan should be cleaned regularly with warm soapy water.

Figure 8. Drain Line

WARNING: All power must be disconnected

before cleaning. The drain pan also serves as cover for hazardous moving parts. Operation of unit without drain pan constitutes a hazard.

NOTE: Always trap drain lines individually to prevent vapor migration.

Refrigeration Piping

Figure 9. Example of

Pipe Support

1. Normally, any straight run of tubing must be supported in at least two locations near each end of the run. Long runs require additional supports. The refrigerant lines should be supported and fastened properly. As a guide, 3/8 to 7/8 should be supported every 5 feet, 1-1/8 and 1-3/8 every 7 feet; and 1-5/8 and 2-1/8 every 9 to 10 feet.

2. When changing directions in a run of tubing, no corner should be left unsupported. Supports should be placed a maximum of 2 feet in each direction from the corner.

3. Piping attached to a vibrating object (such as a compressor or compressor base) must be supported in such a manner that will not restrict the movement of the vibrating object. Rigid mounting will fatigue the copper tubing.

4. Do not use short radius ells. Short radius elbows have points of excessive stress concentration and are subject to breakage at these points.

5. Thoroughly inspect all piping after the equipment is in operation and add supports wherever line vibration is significantly greater than most of the other piping. Extra supports are relatively inexpensive as compared to refrigerant loss.

Figure 10.

Line Insulation

After the final leak test, refrigerant lines exposed to high or low ambient conditions should be insulated to reduce heat loss or gain and prevent the formation of flash gas in the liquid lines. Suction lines should be insulated with 3/4’ wall Armstrong “Armaflex” or equivalent. Liquid lines should also be insulated with 1/2-inch wall insulation or better. The insulation located in outdoor environments should be protected from UV exposure to prevent deterioration of insulating value.

Refrigeration Piping

Figure 11. Piping Connection Layout (MCCU)******

2 sets hard piped

from MCCU to

sandwich cases

2 sets of pre-charged line sets from

IMI Cornelius

2 extra circuits for stores that install

additional. 2 or 4 barrel machines

4”

Hard pipe from MCCU to Bohn

evaporators in ice

vault & vault freezer

4”

4” 4” 4” 4” 4”

1 set of pre-

charged lines

furnished by ice

manufacturer

Hard pipe from MCCU to vault

cooler

Roof Penetrations

All piping and control wiring penetrations are done underneath the fan section of the condensing unit. Refer to building plans for job details of roof penetration scheme. The 4” PVC pipe penetrations shown above is a guide for all parties involved.

Head Pressure Controls

Heatcraft does NOT supply headmaster control for the individual display case circuits. Refer to case manufacturers’ installation instructions for specific provisions needed for head pressure control.

Note: Heatcraft does include headmaster controls on the ice machine circuit. If the ice machine equipment from the vendor includes a headmaster already, it will be necessary to clip the pigtail on the headmaster valve supplied by Heatcraft to disable it from operating and conflicting with the ice machine headmaster.

Leak Detection And Evacuation

Leak Testing

After all lines are connected, the entire system must be leak tested. The complete system should be pressurized to not more than 150 PSIG with refrigerant and dry nitrogen. The use of an electronic type of leak detector is highly recommended because of its greater sensitivity to small leaks. As a further check, it is recommended that this pressure be held for a minimum of 12 hours and then rechecked. For a satisfactory installation, the system must be leak tight.

Leak detection can be carried out in the conventional manner. If HCFC or CFC tracer gas is used, care must be taken to completely remove all traces of the gas prior to introducing HFC’s. Electronic leak detectors are now available that will sense HFC’s. This is considered preferable since it removes the possibility of chlorine remaining in the system after leak testing with HCFC’s and/or HCFC’s. There is a view that even small quantities of chlorine may act as a catalyst encouraging copper plating and/or corrosion and should therefore be avoided.

Within the last several years, manufacturers have developed fluorescent dye leak detection systems for use with refrigerants. These dyes mix with the lubricant and, when exposed to an ultraviolet light “fluoresce,” indicate the location of leaks. Copeland has tested and approved the Rigid “System Safe” dye and found it to be compatible with the compressor materials in systems.

Evacuation

CAUTION: Do not use the refrigeration compressor

to evacuate the system. Do not start the compressor while it is in a vacuum.

Due to the smaller molecule size of HFC’s, they will tend to leak more readily than CFC. Consequently , it is of the utmost importance that proper system evacuation and leak detection procedures be employed. Copeland recommends a minimum evacuation to 500 microns. In addition, a vacuum decay test is strongly recommended to assure there is not a large pressure differential between the system and vacuum pump. Good evacuation processes include frequent vacuum pump oil changes and large diameter, short hose connections to both high and low sides of the system preferably using bronze braided hose.

A good, deep vacuum pump should be connected to both the low and high side evacuation valves with copper tube or high vacuum hoses (1/4” ID minimum). If the compressor has service valves, they should remain closed. A deep vacuum gauge capable of registering pressure in microns should be attached to the system for pressure readings.

A shut-of f valve between the gauge connection and vacuum pump should be provided to allow the system pressure to be checked after evacuation. Do not turn off vacuum pump when connected to an evacuated system before closing shut-off valve.

The vacuum pump should be operated until a pressure a 1,500 microns absolute pressure is reached – at which time the vacuum should be broken with the refrigerant to be used in the system through a drier until the system pressure rises above “0” psig.

NOTE: Refrigerant used during evacuation can not be vented.

Repeat this operation a second time. Open the compressor’s service valves and evacuate the entire system to 500 microns absolute pressure. Raise the pressure to 2 psig with the refrigerant and remove the vacuum pump.

Reclaim all used refrigerant. EP A regulations are constantly being updated. Ensure your procedures follow correct regulations.

Field Wiring

WARNING: All wiring must be done in accordance with applicable codes and local ordinances.

The field wiring should enter the areas as provided on the unit. The wiring diagram for each unit is located on the inside of the electrical panel door. All field wiring should be done in a professional manner and in accordance with all governing codes. Before operating unit, double check all wiring connections, including the factory terminals. Factory connections can vibrate loose during shipment.

1. The nameplate on the unit is marked with the electrical characteristic for wiring the unit.

2. Consult the wiring diagram in the unit cooler and in the condensing unit for proper connections.

3. Wire type should be of copper conductor only and of the proper size to handle the connected load.

4. The unit must be grounded.

5. For multiple evaporator systems, follow the wiring diagrams for multiple evaporator systems carefully. This will assure complete defrost of all evaporators in the system.

6. If a remote defrost Timer is to be used, the Timer should be located outside the refrigerated space.

Note: Control wiring from the Ice Machines must be connected

to the relays in the MCCU Control Panel to properly energize condenser fans.

Table 3. Fan Cycling Relay

Relay # Remote Unit Voltage

R4 Ice Machine 208-240**

Figure 12.

** Hoshizaki ice machines require a 115 volt relay which must be field supplied replacing the factory relay.

Field Wiring

WARNING: All wiring must be done in accordance with applicable codes and local ordinances.

The field wiring should enter the areas as provided on the unit. The wiring diagram for each unit is located on the inside of the electrical panel door. All field wiring should be done in a professional manner and in accordance with all governing codes. Before operating the unit, double check all wiring connections, including the factory terminals. Factory connections can vibrate loose during shipment.

1. The nameplate on the unit is marked with the electrical characteristic for wiring the unit.

2. Consult the wiring diagram in the unit cooler and in the condensing unit for proper connections.

3. Wire type should be of copper conductor only and of the proper size to handle the connected load.

4. The unit must be grounded.

Figure 13. Beacon II Board

Heater

Relay

Fan

Relay

LED

Display

Room

Sensor

Defrost Sensor

Expansion

Valve

Connection

Selection

Buttons

24 V.

Terminal

Block

Suction

Sensor

Suction

Pressure

Beacon II Controller

Installation Tips

• Use a minimum 18 gauge wire for all low voltage connections.

• The Beacon II board get its 24 VAC power supply from a transformer mounted in the electrical end of each evaporator. On 208-240 volt systems the multi-tap transformer is shipped from our factory wired for 240 volts. If your supply voltage is 208 volt you must change to the 208 volt tap on the transformer.

• Refer to wiring schematic shipped on units for wiring. Schematics in this Installation and Operation Manual are typical wiring schematics only.

• Program ALL slave evaporators as SLAVES.

• Evaporators are shipped from our factory with a preset box setpoint temperature of 35°F for air defrost and

-10°F for electric defrost. If your box setpoint temperature requirements are different this must be set using directions outlined under “Room Temperature Control”.

• The suction line temperature sensor MUST be removed from the suction line before brazing the suction

tubing. The sensor MUST then be reinstalled on the suction line after brazing is completed and the tubing has cooled. Insulate when finished.

• The low pressure switch time delay relay, located in the condensing unit, must be set to one minute.

• Some systems may require the crankcase heater to be energized 24 hours prior to start-up. The Beacon II should be de-energized for this period by placing it in the SERVICE MODE. This is done by pressing the “FORCE SERVICE” button twice. To start the system cooling, press the “CLEAR” button.

• Room sensors must be left connected on ALL evaporators.

• A pressure transducer is installed on the evaporator. Do not leak test system above 150 PSI or damage to

transducer could occur.

Condensing Unit

The condensing unit control panel contains the relays, contactors, and a terminal block which is appropriately marked to match the low voltage wiring connections. A sensor for outdoor air temperature measurement is installed on the condensing unit.

Condensing unit must be installed using proper refrigeration practices and codes. Make sure there is good airflow and good clearances around unit.

Evaporator Unit

The evaporator contains the BEACON II controller(s), electric expansion valve(s), pressure transducer, distributor(s), orifice(s), transformer and three sensors. These components are all factory mounted and wired. The three sensors are factory mounted and provide input to the controller from the following: defrost temp., suction temp., room temp.

Each evaporator unit must be installed using proper refrigeration practices and codes. Make sure the piping is correctly sized and properly routed. It is highly recommended that the liquid and suction lines be insulated. There must also be good clearance around the unit. See Heatcraft Refrigeration Installation Manual for more details.

Beacon II Controller

Refrigerant Line Brazing (

The electric expansion valve and the suction temperature sensor on the suction line are factory installed. Care must be taken when brazing these lines at the evaporator.

these components. Heat absorbing compounds or “wet rags” must be used when brazing the refrigerant line connections. The suction line sensor should be removed before brazing.

CAUTION

)

Too high a temperature may destroy

Power Supply

The Beacon II board gets its 24 VAC power supply from a transformer mounted in the electrical end of each evaporator. On 208-240 volt systems the multi-tap transformer is shipped from our factory wired for 240 volts. If your supply voltage is 208 volt you must change to the 208 volt tap on the transformer.

VERY IMPORTANT: If the supply voltage to the evaporator is 208 volts, the primary tap of the transformer must be moved to the 208 volt tap.

If the 24 VAC power supply falls below 18 VAC the system may power down and shut off. When the power supply is corrected to 24 VAC the system will restart after the four minute hold-off period and resume normal operation.

On Beacon II systems the main power for the evaporator can be supplied separately from the power supply of the condensing unit. All wiring, however, must comply with local electrical codes.

This must be done for all the evaporators on that system.

Wiring

Wiring between the condensing unit and the unit cooler(s) will be as follows (see attached wiring diagrams):

• High voltage – There may be high voltage on the defrost heater relay and the fan relay. The evaporator may also be connected to a separate power supply from the condensing unit. See unit cooler spec. plate for ampacity.

• Low voltage – 24V Class II control circuit. A total of five low voltage leads are required to connect the condensing unit to the evaporator (see wiring diagram). Two of these leads are for connecting the outdoor temperature sensor. The other three leads are for connecting the compressor relay, service relay and 24V Common inputs.

• Low voltage wiring must be 18 gauge minimum. For low voltage wiring, maximum distances are:

Condensing unit to MASTER evaporator 500 ft. Smart Controller to MASTER evaporator 1,000 ft.

• Alarm circuit – The onboard alarm is a dry set of NC contacts which closes to indicate an alarm. The type and wiring for the alarm is customer specified. Note that the alarm circuit does not distinguish or indicate what has caused the alarm.

• All wiring must comply with all applicable codes and ordinances.

All 24 volt wiring must be run separate from the line voltage wiring.

Box Temperature Control Settings

• There is an on board room thermostat on the Beacon II board which can be adjusted to the desired

room temperature. The temperature differential is 2°F. Temperature Differential When a system is in the cooling mode and the box setpoint is 35°F, the system will continue to cool until

the box temperature gets to 34°F. At this point the compressor will pumpdown and shut off. The system will restart cooling when the box temperature has risen to 36°F.

It is important to note that Beacon II has a minimum 2-minute “ON” time and a minimum 4-minute “OFF” time. This means that the system will run in the cooling mode a minimum of 2 minutes even if the setpoint temperature is met. In applications where the system is grossly oversized, the box temperature could go below the differential temperature before the system cycles off.

In the “OFF” cycle, the system will be off for a minimum of 4 minutes even if the box temperature goes above the differential temperature before cooling will be restarted.

• The on board room thermostat is factory set at 35°F for air defrost systems and -10°F for electric

defrost systems.

+ 33 hidden pages

Bohn ADT130BHB2N2K Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual