Bohn H-IM-BEACON Installation Manual

Part Number 25001501

INSTALLATION & OPERATING

INSTRUCTIONS

FOR

02/01

®

2175 West Park Place Blvd. • Stone Mountain, GA 30087 • [phone] • Fax: [phone]

BEACON CONTROLLER

QUICK GUIDE

Installation, Start-Up, Operation, Troubleshooting

Installation

•Use 18 gauge wire for 24-volt connections between evaporators and condensing unit.

•Remove suction line sensor before brazing; reinstall suction sensor after brazing is completed and suction

line has cooled; insulate with insulation provided.

•If an electric defrost evaporator is being applied in a medium temperature application, have the nozzle size
checked for proper sizing.

Condensing Unit

•Set transformer primary connection for correct supply voltage (208V or 230V).

•Check low pressure switch time delay relay for correct adjustment to 2 minutes.

•Check low pressure switch for correct adjustment to 0 psig cut-out / 10 psig cut-in.

Evaporator

•Check black jumpers for system settings; change to match your application requirements.

•Board are shipped from factory set for 35°F medium temperature or -10°F low temperature; change resistor

for set-point temperature to match application requirements.

•Check sensor connections on board; confirm that sensors are plugged onto correct terminals.

•Check expansion valve (EXV) connections on board; confirm that wires are plugged onto correct terminals.

•If system has multiple evaporators, check master/slave wiring: Wire multi-out from master to multi-in on

slave, then from multi-out of slave to multi-in of master.

Start-Up

•After system evacuation add correct refrigerant. It may be necessary to adjust time delay relay (TDR) to 10
minutes, temporarily, to allow system charging. Readjust TDR back to 2 minutes when done.

•In ambient above 75°F, charge unit to a clear sight-glass. In colder ambients, raise discharge to 105°F
condensing and charge to a clear sight-glass.

•At initial start-up, system may cycle off on low superheat. Let system cycle. It may take 4 to 5 cycles for
system to settle out.

•If Smart Controller is used, make sure “Defrost End Temp.” on the Beacon board is set to 50°F.

•If multiple evaporators are connected to a condensing unit, the room sensor must be connected to the

master evaporator only. Disconnect the room sensor from all the other boards.

Sequence of Operation

Cooling

•The Beacon system has a built-in 4 minutes hold on / 4 minutes hold off cycle. The system will “run” in
cooling a minimum of 4 minutes and stay “off” a minimum of 4 minutes.

•When power is first applied, the system will not start for 4 minutes.

•After 4 minutes, the expansion valve opens and the compressor contactor circuit is energized shortly after

the valve opens.

•When the system is cooling, the expansion valve is adjusted at 2 minutes intervals to obtain the set
superheat. If the superheat falls too low, the expansion valve is adjusted at a much faster rate to bring the
superheat up.

•When the room temperature is obtained, the expansion valve is closed and the system is pumped down until
the low pressure switch opens or 2 minutes have elapsed.

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BEACON CONTROLLER

QUICK GUIDE (cont’d.)

Defrost

•The actual defrost time is determined when power is first applied to the system as well as the number of
defrosts per day. If a Smart Controller is used, the actual defrost times are programmed into the Smart
Controller.

•At defrost the expansion valve closes, then the system pumps down until the low pressure switch opens or 2
minutes have elapsed. The compressor is now off.

•The fan motors are shut off and the heater contactor on the Beacon board is energized. On systems with
higher than 30 amps, the heater contactor on the board is used to energize a larger amperage contactor.

•Defrost is terminated when the evaporator coil sensor reaches the defrost termination temperature. The
heaters are turned off and the system goes through a short drain-down period.

•At the end of the drain-down period, the expansion valve opens and the compressor starts shortly after. The
fans do not run during this re-freeze period.

•At the end of the re-freeze, the fan motors start and the system is back in the cooling mode.

Trouble-Shooting

•System flashes “low pressure, high pressure, oil pressure fault”

-Check system for refrigerant leak

-Check oil level in compressor

-Check system for non-condensable

-Check low pressure switch for correct adjustment to 0 psig cut-out / 10 psig cut-in

-If ambient is below 50°F, may need to addd pressure fan cycling switch

•System flashes “superheat sensor shorted or open”

-Change evap-in and evap-out sensors

•System flashes “room temp sensor, discharge sensor, defrost termination temp sensor shorted or open”

-Change sensor as indicated

•System flashes “superheat low”

-Check evaporator coil circuits for uneven feeding; if circuits are not feeding evenly 1) check nozzle
sizing for the application, and 2) expansion valve may be defective

-Check if evap-in and evap-out sensors are plugged into correct terminals on the board

-Check if system is overcharged

•System cooling, but box temperature not met

-If a low temp evaporator is being used in medium temp application, check nozzle size

-Check if transformer is on the correct voltage tap

-Check for low refrigerant charge

-Check pump-down switch for incorrect wiring

-Check if discharge temperature is above 225°F; remove discharge line sensor from discharge line

-Disconnect evaporator coil sensor from the board

-Check value of room temperature pot setting; if value is correct, pot may be defective. Add fixed
resistor

•System “off” and will not run

-Check if room sensor is connected on the board

-Check if system has a “pump-down” switch; put switch in “normal” position

•If system has a Smart Controller

-Check to make sure room sensor is connected only to Smart Controller

-Check wiring of multi-in and multi-out to be per wiring in Installation & Operation manual

-Check program in Smart Controller; range must be on “lo” for low temp applications and “hi” for
medium temp applications

3

BEACON CONTROLLER

INSTALLATION INSTRUCTIONS

Before Installing or Starting Unit:

• Use a minimum 18 gauge wire for low voltage connections to cooler, condensing unit and Smart Controller.

• Transformer is shipped wired for 240V primary; if your supply voltage is 208V, change to the 208V tap.

• Refer to wiring schematic shipped on units for wiring; schematics in the Installation & Operation Manual are
typical schematics.

• If desired box temperature is different from preset factory temperatures (35˚F air defrost, -10˚F electric
defrost), see “Room Temperature Control”, Page 5 for options.

• Check Beacon board jumper settings to ensure that they match the application requirements; factory jumper
settings are shown on Table 3, Page 14.

• The low pressure switch time delay relay, located in the condensing unit, must be set at 2 minutes.

• Make sure all wiring connections are correct and tight.

• 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 is
cooled.

• The Beacon timing for evaporator defrost is based on when power is first applied to the Beacon board (i.e. if
4 defrosts per day will occur at 9:00 p.m. and every 6 hours thereafter) the system will perform a defrost.

• Some systems may require the crankcase heater to be energized 24 hours prior to start-up; the Beacon
should be de-energized for this period by disconnecting the 24V lead to the condensing unit terminal block.
To start the system, this 24V lead must be re-attached.

CONDENSING UNIT

The condensing unit control panel will contain the relays, contactors, transformer and terminal block appropri­ately marked to match the wiring connections to be made.

UNIT COOLER(S)

Each unit cooler(s) will contain the Beacon controller, an electric expansion valve, a distributor, orifice, and
four thermistor sensors. These components are all factory mounted. The 4 sensors provide input to the
controller from the following: evap-in, evap-coil, evap-out and entering room air temperatures.

MASTER/SLAVE CONNECTION

The Beacon Controller allows multiple unit coolers to be connected in a master/slave configuration. Up to 6
Low Profile evaporators or up to 3 Medium Profile evaporators can be connected in a master/slave
configuration when using the standard factory shipped transformer. When connected in a master/slave
configuration, the entering room sensors must be disconnected from each of the slave units. When
connected to the Optional Smart Controller, the Optional Smart Controller controls the master and all the
slaves. (See Master/Slave wiring connections on typical wiring diagrams.)

During master/slave operation, there could be a delay in the reaction time of each slave to the master of up to
1 minute. The length of time is dependent on how many slaves are connected to the system.

ß

4

BEACON CONTROLLER

REFRIGERANT LINE BRAZING (CAUTION)

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

may destroy these components. Heat absorbing compounds or “wet rags” must be used when braz­ing the refrigerant line connections and the suction line sensor removed per above instructions

WIRING

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

• High voltage - To the defrost heaters (if present) and/or fan motors. See unit cooler spec plate for ampacity.
The evaporator may also be connected to a separate power supply.

• Low voltage - 24V (18 to 30) VAC Class II control circuit. A total of 5 low voltage leads are required to
connect the condensing unit to the evaporator. Two of these leads are for connecting the compressor
discharge sensor. The other 3 leads are for connecting the compressor relay and the 24V transformer. All
24 volt wiring must be separated from the line voltage wiring.

• Compressor discharge line sensor - Use 18 gauge wire. Must be run separate from other high voltage
power wiring.

• Smart Controller (Optional) - Use 18 gauge wire. For extra long runs, 16 gauge wire may be required. Low
voltage wiring must be run separate from other high voltage power wiring.

• Slave unit(s) (if used) - Connect the
unit and the 24V (18 to 30) VAC from the master unit to the slave unit. (See wiring diagram.)

• Alarm circuit - The onboard alarm is a dry set of NC contacts which closes to indicate an alarm. Type and
wiring for the alarm is customer specified. Note that the alarm circuit does not distinguish or indicate what
has caused the alarm. (See “ALARMS”.)

multi-out

terminal on the master unit to the

Too high a temperature

.

multi-in

terminal on slave

Note: All wiring must comply with all applicable codes and ordinances.

ROOM TEMPERATURE CONTROL

Three methods are available:

• Each Beacon board is shipped with a fixed resistor (attached) that controls the room temperature set­point. Air defrost boards are set for 35˚F with a 15K ohms resistor. Electric defrost boards are set for -10˚F
with a 100K ohms resistor.

• In the packet are additional resistors which can be used for other room temperature set-points. These
resistors are color coded. The table below shows the settings.

Resistor Color Resistor Value Set-point

Tape Ohms Temperature

Black 100K -10˚F

Green 70K 0˚F

White 30K 20˚F

Blue 20K 30˚F

Yellow 15K 35˚F

Red 10K 40˚F

• To change the room set-point, remove the resistor attached to the Beacon board and attach the resistor
value required for your set-point temperature. If you need a value not shipped in the packet, you may
purchase a 1/8W to 1/2W resistor from an electronics store (i.e. RadioShack), for the ohm values shown.

• These resistors will control the room temperature at the approximate temperatures shown. These values
are also to be used for setting the Beacon board thermostat pot.

5

BEACON CONTROLLER

ROOM TEMPERATURE CONTROL (Cont’d.)

• Another method of setting the room set-point is to use the Beacon board thermostat pot. If a value other
than that available by using a fixed resistor is required, the pot on the Beacon board can be used. First,
you must discard the fixed resistor. Then, using a digital ohmmeter, measure the resistance between the
“X” and “200K” as indicated in the illustration below. Use a screwdriver to turn the thermostat pot until the
resistance value is obtained for the desired room temperature (according to Table 1). Install the jumper
(supplied in the bag) across the terminal marked “X” when finished.

• The Beacon Smart Controller. See Beacon Smart Controller Installation & Operating Instructions (Part
#25004101) for more details.

TABLE 1

Carbon Film Fixed Resistor selections that will control the room temperature at the approximate temperatures
shown. These values are also to be used for setting the Beacon board thermostat.

Application Temperature °F *Ohms
Low Temperature -25 182K

Electric Defrost -20 150K

-15 120K

-10 100K

-5 85K
0 70K

Medium Temperature 20 30K
Electric Defrost 25 25K

30 20K

Medium Temperature 35 15K
Air Defrost 40 10K

45 8K
50 5K
55 2K
60 0K

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BEACON CONTROLLER

BEACON MICROPROCESSOR SETTINGS (See Table 3 for more details.)

Selections to be made by applying movable jumpers:

Defrost cycles or time - Controlled by the board in master unit only. Selection must be either “elapsed”
time or “run” time. If “elapsed” time is selected, the number of defrost must be set at either 1, 2, 4 or 6 per
day. If no selection is made, default is 4 defrosts per day. If “run” time is selected, the compressor run
time must be set at either 2, 3, 6, or 12 hours. If no selection is made, default is 3 hours compressor run
time.
Superheat - Controlled by each board in each evaporator. Selection must be either 6, 8, or 12° F. Close
coupled systems will require the higher superheat selections. If no selection is made (no movable jumper
applied) the preprogrammed default is 8° F superheat.
Defrost fail-safe - Controlled by board in master unit. Each board should have the same setting on
multi-evap systems. Must be either 10, 20, 30, 40, or 60 minutes . If no selection is made, default is 30
minutes.
Medium or low temperature - All evaporators must have the same settings for the application. For
example, on a master/slave application, all the units must have the same setting. (i.e. for medium tem­perature they must all be set at medium).

Test or normal - Factory set at normal. Test is also used to check board for proper function.
Type 2 or type 1 - Are not used.
Reset time or normal - Resets all internal timers back to zero as though the unit was just powered up.

Keep jumper on normal except for momentary move to reset position. If jumper is left on RESET position,
the four minute off time will be set to zero on power up.
Forced defrost or normal - Forced defrost is used momentarily to force an extra defrost. It will not reset
the regularly scheduled defrost. Select the normal position. Note that, when initiated, the four minute.
“Hold off” and “Hold on” cycles will be in effect.
Defrost end temperature - Select either 50, 70, or 90° F. If no selection is made, preprogrammed
default is 50° F.

Do not select

.

REFRIGERANT CHARGING

Be aware that the Beacon system does not normally require a condenser flooding valve and is capable of
operating at lower than normal condensing temperature. The condensing pressure will be raised by fan
cycling only when needed to lower evaporator superheat to the selected value.

The system does not require a winter charge. If the ambient is above 75° F, charge just until the sight-
glass clears. When charging in colder ambients, it will be necessary to reduce the amount of air going
through the condenser with the fans still running. Simply reduce the effective face area to raise the discharge
pressure above the equivalent 105° F. condensing temperature and then proceed to charge to clear the sight­glass. Return to full condenser face area and allow the system to balance.

7

BEACON CONTROLLER

OPERATING INSTRUCTIONS

REFRIGERATION MODE

START UP

1. Check all wiring connections to be sure they are correct and tight.

2. Check voltage taps on transformer. The transformer is shipped wired for 240. If your supply voltage is 208
volt systems, charge to 208 voltage tap.

3. Check setting of time delay relay in condensing unit. It should be set at two minutes (the third marker).

4. Check the low pressure switch setting. It must be set to 0 PSIG cut out, 10 PSIG cut in, to allow start and
operation, especially in cold ambients.

5. At initial start-up, the system may cycle off at 4 minutes and display a low superheat error, then restart
itself. This cycle may be repeated a few times. Do not shut the system off. Let the system run, as it may
take a few cycles for the electric expansion valve to attain the correct setting for the desired superheat.

6. Liquid line should always be insulated.

Ambients above 50° F

At the initial application of power to the system, the compressor and the evaporator fans will be in a four
minute hold-off cycle and will not start immediately. When there is a call for cooling, the compressor starts
and the electric expansion valve (EEV) stays closed for 12 seconds. After 12 seconds, the EEV goes to
approximately half open and the compressor is put in a four minute “hold-on” cycle. (This means that the
compressor will run for a minimum of four minutes before shutting off.)

When the room thermostat setting becomes satisfied and if the compressor ran for at least four minutes, the
EEV will close and the compressor will pumpdown, then shut off. The evaporator fans will continue to run.

When the room sensor detects a rise in temperature of approximately 2°F, and the compressor has been off
for at least four minutes, the EEV opens to its last position 15 seconds before the compressor starts. Super­heat adjustments at two minute intervals will then follow. During this time, the compressor will be on a
minimum four minute “hold-on” cycle. If the superheat drops to +2°F at anytime, the valve will be adjusted at
45 second intervals.

If the compressor discharge line sensor reaches 225° F for four minutes, the superheat will be lowered
temporarily, overriding the normal superheat routine to effectively keep the compressor discharge line tem­perature from going any higher. “Discharge high” fault will be displayed and the system will continue to
operate. A service person should check system to determine cause for high discharge temperature.

8

BEACON CONTROLLER

Ambients below 50° F and above 10° F

At the initial application of power to the system, the compressor and the evaporator fans will be in a four
minute hold-off cycle and will not start immediately. When there is a call for cooling, the compressor starts
and the electric expansion valve (EEV) stays closed for 12 seconds. After 12 seconds the EEV goes to 7/8
open and the compressor is put in a four minute “hold-on” cycle. Superheat adjustments at two minute
intervals will then follow.

When the room thermostat setting becomes satisfied and if the compressor ran for at least four minutes, the
EEV will close and the compressor will pump-down and shut off. The evaporator fans will continue to run.

When the room sensor detects a rise in temperature of approximately 2°F and the compressor has been off
for at least four minutes, the EEV will open to it’s last position, 30 seconds before the compressor is started.

Ambients below 10° F

At the initial application of power to the system, the compressor and the evaporator fans, will be in a four
minute hold-off cycle and will not start immediately. When there is a call for cooling, the compressor starts
and the electric expansion valve (EEV) stays closed for 12 seconds. After 12 seconds the EEV goes to full
open, and the compressor is put in a four minute “hold-on” cycle.

When the room thermostat setting becomes satisfied and if the compressor ran for at least four minutes, the
EEV will close and the compressor will pump-down until the low pressure switch trips or one minutes has
elapsed. The evaporator fans will continue to run.

When the room sensor detects a rise in temperature of approximately 2°F and the compressor has been off
for at least four minutes, the EEV will open to it’s last position, 30 seconds before the compressor starts.

CONDENSER FAN CYCLING

Beacon condensing units will have pressure fan cycling and ambient fan cycling as standard. On one fan
condensing units, pressure fan cycling, with a setting of 150 psig cut-out and 200 psig cut-in is used. On two
fan condensing units, one fan will be controlled by an ambient switch, set at 50°F cut-out, and the other fan
will be controlled by the pressure fan cycling switch.

9

BEACON CONTROLLER

PUMP-DOWN

At the end of each cooling cycle, when the box temperature is met, the system will pumpdown and shut off.
To pumpdown, the EEV closes and the compressor pumps down until the low pressure switch trips the unit

off, or two minutes have elapsed. While in the off cycle the system will initiate a short pump-down at four
minute intervals, if the low pressure switch is closed, to ensure that any refrigerant leakage, will not cause a
problem.

To Manually Pump-Down System

The system can be pumped down for service by closing the liquid line service valve in the condensing unit,
then closing the suction line service valve when the system trips on the low pressure switch.

or

Install a switch that will interrupt the circuit to one wire of the room sensor to the Beacon board. This will
cause the system to pump down and shut off. The system will not restart until the switch has re-made the
circuit to the room sensor.

Systems with Optional Pump-Down Switch on the Condensing Unit

The low pressure switch time delay relay will have to be adjusted from the factory set 2 minutes to 0 minutes
before flipping the pump-down switch. After normal operation of the system is restored, the low pres-

sure switch time delay relay must be adjusted back to the 2 minute setting.

CHECKING OPERATION OF EXPANSION VALVE (EEV)

The expansion valve position is indicated by a 0 to 5 volts DC signal. At 0 Volt the valve is closed and at 5
volts the valve is fully open. At values between 0 and 5 Volt, the valve will be opened proportionately. By
using a volt meter to measure the DC volts across the pins marked “EXV TEST” (bare pins near LED) on the
Beacon board, a determination can be made if the valve is open or closed. This must be measured while the
unit is cooling.

ELECTRIC DEFROST MODE

If elapsed time has been selected (this works just like a time clock), the number of defrosts per day will
depend on the number selected on the controller (i.e. 1, 2, 4 or 6). If run time has been selected, the number
of defrosts per day will vary depending on the compressor run time (i.e. 2, 3, 6 or 12 hr.).

When a defrost is initiated, the EEV valve closes, the compressor is allowed to pump-down (see pump-down
description), the evaporator fans are cycled off and the defrost heaters are energized. The master and all
slave controllers must terminate their defrost, either on temperature or time, before the master controller will
end the defrost cycle. There is a 60 second condensate drain-down time before the compressor is started,
followed by a 60 second evaporator fan hold-off time (fan delay). After this sequence, the controller(s) are
back in the refrigerating mode and the EEV(s) open to the position prior to defrost.

AIR DEFROST MODE

Usually the cycling on the thermostat will suffice to defrost the coil(s) when operating at room temps between
35° & 45°F. However, it will be necessary to set certain parameters. Recommended values when operating
near the 35° F range are as follows: select elapsed time, 2 defrost per day, 40 min. fail-safe & 50° F defrost
end temp. When operating near the 45° F range, it is advisable to minimize the effect of the defrost by
changing to a 10 min. fail-safe & 50° F defrost end temp. Note: These are only recommended settings.
Other settings are available on the Beacon board.

10

BEACON CONTROLLER

STATUS INDICATOR

There is a red status indicator light on the Beacon board. This light has a controlled blink sequence to
indicate modes such as cooling, superheat, off, defrost, or error. (See status light blink sequence chart.)

•COOLING/SUPERHEAT: During the cooling mode, the light will blink off for two seconds, on for two sec-

onds, off for two seconds followed by a rapid sequence of blinks that if counted will indicate superheat.

•OFF CYCLE: During the thermostat off cycle, the light will blink off for seven seconds and on for one sec-

ond, which will then repeat.

•DEFROST: During defrost, the light will blink off for one second and on for one second, which will then

repeat.

ALARMS

Beacon provides a set of dry contacts that are normally closed, for use in controlling an alarm. These
contacts can be connected to a light, a buzzer or a bell., which will be activated when an alarm condi­tion occurs.

When the Beacon is energized, the alarm contacts are OPENED. When an alarm condition is de­tected, the contacts are CLOSED.

Conditions under which the alarm contacts will close are:

•Power failure on or to a Beacon board.

•Room temperature of 16° F or more above thermostat set-point or 4° F below thermostat set-point, for more

than 1 hour (master controller only), when not in defrost. System will pump-down and shut off. It will restart
after four minutes.

ERROR INDICATOR & STATUS LIGHT

At initial power up, each Beacon board checks for system errors. The system error check involves checking
the various temperature sensors to determine whether any of these sensors are shorted or open.

The system will pump-down and cycle off and will not restart until the fault is cleared or the circuit breaker
reset, for the following conditions:

Superheat sensor shorted or open
Room temperature sensor shorted or jumper not installed

The system will pump-down, cycle off and try to restart, after the four minute “hold off” period, for the following
fault conditions:

Superheat too low
High pressure, oil pressure or low pressure cut-out

11