Master-Bilt Master Controller 2.0 Installation Manual

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Master Controller 2.0v19

Reverse Cycle Defrost System

Installation & Operations Manual

An Electronic Microprocessor-Based

Electric/Mechanical Expansion Valve Refrigeration Control System

With TCP/IP Internet Monitoring Feature

August 2013

PN 888-88889

IMPORTANT NOTICES

• Read this manual before installing your Master Controller 2.0

system. Keep the manual and refer to it before doing any service on the equipment. Failure to do so may result in personal injury or waive warranty of damaged equipment.

• Modifications to existing equipment are subject to approval by Master-Bilt and must be explicitly written. There are no implied flexibilities designed into this product.

• The following points apply unless overwritten and approved by the Master-Bilt engineering department:

o Maximum distance of wires between the evaporator and the Master

Controller 2.0 MUST not exceed 40 ft.

o The Master Controller 2.0 MUST be mounted on the neighborhood

of the vestibule entrance door for below -40oF extra low temp freezer

o All sensor wires MUST be in separate metal conduit from power

wiring and control wiring for below -40oF extra low temp freezer

• Due to continuous product enhancements, Master-Bilt reserves the right to make engineering changes and change specifications for product improvement without notice.

TABLE OF CONTENTS

INTRODUCTION...................................................................................................................4

WARNING LABELS AND SAFETY INSTRUCTIONS...........................................................5

APPLICATIONS ....................................................................................................................5

MASTER CONTROLLER......................................................................................................6

Description .................................................................................................................6

Factory-Mounted Parts ...............................................................................................8

Features .....................................................................................................................9

Sequences of Operation...........................................................................................10

OFF MODE

COOL MODE

DEFROST MODE

Scheduled Defrost

Demand Defrost

COIL DRAIN MODE

FAN DELAY MODE

SAFETY MODE

BOND CONTROLLERS FROM FRONT PANEL

PEER TO PEER MODE

ALTERNATING MODE

VARIABLES

MANUAL MODE

TYPICAL SETPOINTS PARAMETER

ALARM DISPLAY

Multiple Evaporator Configuration ............................................................................13

Definition of On-Board Symbols ...............................................................................14

Setting Parameters by On-Board Pushbuttons ........................................................17

START UP

.........................................................................................................10

......................................................................................................10

.................................................................................................11

......................................................................................11

........................................................................................11

Manual Defrost

..........................................................................................12

...............................................................................................12

....................................................................................................12

..........................................................................................13

...........................................................................................14

STATUS, DEFAULT AND READING DISPLAY

........................................................................................................15

...................................................................................................15

..........................................................................16

.................................................................................................17

..............................................................13

...............................................................14

Temperature Sensors...............................................................................................19

SENSOR SERVICE INSTRUCTIONS

..........................................................................19

Pressure Transducer ...............................................................................................20

Charging the Master Controller 2.0 Refrigeration System .......................................21

Technical Notes........................................................................................................22

REVERSE CYCLE DEFROST ...........................................................................................23

General Information..................................................................................................23

Advantages ..............................................................................................................23

Factory-Installed Parts..............................................................................................23

Eliminated Parts .......................................................................................................24

Defrost Time .............................................................................................................24

Charging a Master Controller 2.0 System Equipped with Reverse Cycle Defrost ...24

ELECTRIC WIRING ............................................................................................................24

TYPICAL WIRING DIAGRAMS

...................................................................................... 25-27

TROUBLESHOOTING GUIDE............................................................................................28

Troubleshooting Electric Expansion Valve ..............................................................29

MASTER-BILT PART NUMBERS .......................................................................................29

INTRODUCTION

Thank you for purchasing a Master-Bilt Master Controller 2.0 for Electric or Reverse Cycle Defrost system. This manual contains important instructions for installing, using and servicing the system as well as a parts list. Read this manual carefully before installing or servicing your equipment.

DANGER

Improper or faulty hook-up of electrical components of the refrigeration units can result in severe injury or death.

All electrical wiring hook-ups must be done in accordance with all applicable local, regional or national standards.

NOTICE

Installation and service of the refrigeration and electrical components must be performed by a refrigeration mechanic and/or a licensed electrician.

The portions of this manual covering refrigeration and electrical components contain technical instructions intended only for persons qualified to perform refrigeration and electrical work.

This manual cannot cover every installation, use or service situation. If you need additional information, call or write us:

Customer Service Department

Master-Bilt Products

Highway 15 North

New Albany, MS 38652

Phone: 800-684-8988

Fax: 866-882-7629

Email: service@master-bilt.com

WARNING LABELS AND SAFETY INSTRUCTIONS

This is the safety-alert symbol. When you see this symbol, be alert to the potential for personal injury or damage to your equipment. Be sure you understand all safety messages and always follow recommended precautions and safe operating practices.

NOTICE TO EMPLOYERS

You must make sure that everyone who installs, uses or services your refrigeration is thoroughly familiar with all safety information and procedures.

Important safety information is presented in this section and throughout the manual. The following signal words are used in the warnings and safety messages:

DANGER: Severe injury or death will occur if you ignore the message.

WARNING: Severe injury or death can occur if you ignore the message.

CAUTION: Minor injury or damage to your refrigeration system can occur if you ignore the message.

NOTICE: This is important installation, operation or service information. If you ignore the message, you

may damage your refrigeration system.

The warning and safety labels shown throughout this manual are placed on your Master-Bilt refrigeration system at the factory. Follow all warning label instructions. If any warning or safety labels become lost or damaged, call our customer service department at 800-684-8988 for replacements.

This label is on the housing of the Master Controller 2.0 typically located on an evaporator coil.

APPLICATIONS

Master Controller 2.0 Electric/Reverse-Cycle Defrost systems are designed to control Master-Bilt made condensing units and evaporators for freezer and cooler applications. Each system contains a condensing unit, evaporator(s) with Master Controller 2.0 board(s), Mechanical/electric expansion valve(s), pressure transducers, temperature sensors, reverse cycle valve and operational controls.

MASTER CONTROLLER

Description

The Master Controller 2.0 is a custom-designed microprocessor-based electronic controller for Master-Bilt refrigeration products. The controller caple to control an electric expansion valve in response to evaporator superheat and return air temperature. The hardware and input/output descriptions and connections of a Master Controller 2.0 are shown below.

Figure 1 . Master Controller 2.0 Board Layout.

• SEI or SER Terminals. Sporlan SEI and SER type electric expansion valves are currently used for all applications. There are 1596 nominal steps for entire valve stroke.

• Pressure Transducer is mounted at the evaporator suction header to measure saturated suction pressure in absolute value but displayed in gauge pressure in PSIG. The suction pressure is converted to evaporating temperature. The difference between outlet temperature and evaporating temperature is the true superheat displayed as “SUPH”.

• Defrost Termination Temperature Sensor TS3 is mounted downstream of the distributor tube after the valve and close enough to the evaporator coil to measure defrost termination temperature during defrost cylce. Figure 2 on the previous page shows the sensor locations of the evaporator and the controller.

• Outlet/Fan Cut-In Temperature Sensor TS1 is mounted on the suction line about 6” to 10” away from the evaporator to measure outlet temperature during cooling cycle and to serve as evaporator fan cut-in temperature sensor. The sensor is at a 2 or 10 o’clock position on the suction line. The default value of the fan cut-in temperature is pre-set at 20oF for commercial refrigeration application.

• Room Temperature Sensor TS2 is typically mounted with a plastic tie at the drain pan on the side of the evaporator return air. It is located around the middle of the evaporator to allow even air flow across it. If necessary, it can be relocated to a spot with better representation of the cold room temperature.

• Four Digit LED Display is used to show status of the controller, set point values and temperatures.

• Green Amber and Red LED Status Indicators. The green LED will be on when the compressor relay is

energized. The green LED will blink when the air temperature is satisfied, but the compressor minimum run timer or minimum off timer has not yet timed out. The red LED indicates a critical alarm has occurred (Low Pressure alarm). The amber LED indicates all other alarms.

• Six Push Buttons are used to display set points and status as well as to reset operational parameters like room temperature, defrost mode, number of defrosts, etc. Their functions can be also performed by using the TCP/IP interface.

• Two 20 Amp, 240 VAC NC/NO Relays. One relay is used for the defrost heater when the heater load is less than 20 amp. It will be wired to defrost heater contactor when heater load is over 20 amp or three phase heaters. For a

reverse cycle defrost system, it is wired to a 40VA transformer that provides 24VAC power to the reversing valve solenoid coil. The other relay is used to switch evaporator fans ON and OFF. A fan contactor will be used if

the fan motor is lager than 10 amps or three phase or the voltage is different from control voltage.

• One 3 Amp, 240 VAC NC/NO Relay is used for the compressor contactor or liquid line solenoid.

• One 3 Amp, 240 VAC NC/NO Relay is an option for an external alarm system. The customer can decide what

type of a physical alarm is used. This relay is energized when the controller is powered on. Whenever the controller gives an alarm, the relay will be de-energized. For example, a technician can connect a phone alarm system to this relay. When there is an alarm, the alarm system can dial in his pager or cellular phone.

• One RJ-45, TCP/IP Ehternet Port is used for Peer to Peer system or an alternating system communication requiring ethernet connection. It is also used to communicate with a Laptop, internal network, or the internet.

• Power Input 120 or 208/240 VAC. For 120 VAC input, jumper between pins 1 and 2 of ‘Voltage Jumper’ connector and jumper between pins 3 and 4 of ‘Voltage Jumper’ connector. For 208/240 VAC input, jumper between pins 2 and 3 of ‘Voltage Jumper’ connector.

Pressure Transducer

Evaporator

Evap Coil In/ Defrost Temp. Sensor

Liquid Line

Suction Line

Evap out / Fan Delay

Temp Sensor

Room Temp Sensor

T1 T2

Distributor

Electric Expansion Valve

ADVANCED MASTER CONTROLLER

Figure 2.

Factory-Mounted Parts

• A controller board, an Electric/Mechanical expansion valve, a pressure transducer, and three temperature sensors for single evaporator system (standalone or alternating) or peer (multiple evaporator system) evaporator are pre-mounted at the factory. . For a multiple evaporator system, only 1 evaporator is required to have an air temperatue sensor. For reverse cycle defrost, a 24 VAC 40VA transformer is mounted at standalone or master evaporator to provide power 24VAC to the four-way reversing valve mounted in the condensing unit. The control circuit and power supply are pre-wired to the terminal board of the evaporator. The board is molded in epoxy to avoid excessive moisture in cold room.

• A 4-way reversing valve, operating at 24 VAC, is installed in a reverse cycle defrost equipped unit. A transformer is also installed in one of the evaporators to supply 24VAC to the 4-way reversing valve.

• Peer to Peer controls can be connected directly to each other, using a CAT-5E cable, if there are only 2 controllers. The controllers must be connected through an Ethernet switch or router if 3 or more controllers are on the system. The controllers must be bonded together. A technician should install the CAT-5E cable from the controllers to the Ethernet switch or router and bond the controllers. All components are factory tested. A technician should check all the wiring and settings for proper operation after installation.

Features

• One of the most energy-saving features of the Master Controller 2.0 Reverse Cycle Defrost system is free floating head pressure. A head pressure control is not installed on Master Controller 2.0 systems. Without this control, compressors work at the highest efficiency at the lowest possible condensing pressure rather than at the limited pressure level typically found in conventional systems using a head pressure control valve for low ambient environments. For more energy saving information, go to www.master-bilt.com/pdfs/master_controller_vs_standard_system.pdf.

• Option for Mechanical Expansion Valve, or Electronic Expansion Valve

•

With the electric expansion valve; the refrigerant flow of the electric expansion valve is modulated by the true superheat, or the difference of evaporator outlet and evaporating temperatures.

•

The room temperature sensor replaces the conventional temperature control. The temperature is set with the pushbuttons on the Master Controller 2.0 board or through the web page. The default temperature must be checked during the first startup of the machine against actual application temperature. Default must be re-set to actual application temperature if there is a discrepancy.

•

Evaporator Fans cycle during compressor off mode, and options for electric defrost heaters to cycle onand-off durring defrost for addition energy saving.

•

The on-board timer is used for run time control and scheduling defrosts. No mechanical defrost timer is necessary for this system. Once the power is turned on, the timer starts counting.

•

The Master Controller 2.0 has the capability to perform scheduled defrost or demand defrost for either Reverse Cycle hot gas defrost, or Electric defrost.

When the scheduled defrost scheme is chosen, the on-board timer is used for scheduled defrosts. The system works in the same fashion as a regular conventional system with mechanical defrost timer.

When the demand defrost is chosen, the controller will not initiate a defrost unless it is needed. The low temperature system is pre-set with demand defrost.

• The demand defrost scheme is a pioneer design by Master-Bilt for freezer applications. Extensive lab tests indicate that many unnecessary defrosts are eliminated and energy consumption reduced when using demand defrost compared to using a conventional refrigeration system equipped with a mechanical defrost timer.

• The operational status of modes, room temperature and alarms is displayed on the four-digit on-board display.

• Manual defrost is available on standalone and Peer to Peer systems.

• All components are factory-mounted, pre-wired and tested to save on-site installation labor and reduce

chance of installation errors.

• The superheat set point has a wide adjustability range 5° to 20 oF. This range allows the controller to meet different customers’ needs, and require less refrigerant charge for winter operation than conventional refrigeration unit when no head pressure valve is installed in the condensing unit.

• The controller can be used in low, medium and high temperature applications. The internal programming will recognize the input of room temperature set point (RMSP) and automatically select appropriate segments of the program for the application.

• The patented reverse cycle defrost control (United States Patent 7,073,344) reduces defrost energy usage by up to 80% and decreases defrost time from 20-45 minutes (freezer equipped with electric heaters) to 3-5 minutes in a freezer or 11/2 – 2 minutes in a cooler with a completely clean defrost.

• Maximum operating suction pressure can be controlled by the electric expansion valve eliminating the crankcase pressure regulator for some applications.

• Minimum operating suction pressure provides additional compressor protection.

Sequences of Operation

START UP

When power is applied to the board, the controller closes the valve. The controller will display ‘STUP’ on its fourdigit display for five seconds. It will then display ‘CKFN’ on the four-digit display for 10 seconds. The evaporator fans will be on for the first 15 seconds allowing a service technician time to check them. The controller will then turn the fans off and check each sensor. The controller will check the pressure transducer for a short or open. It will display ‘CKPR’ on the four-digit display for three seconds. If the sensor fails, the controller will display an alarm and go to safety mode for a failed sensor. If the sensor passes, it will display ‘OKPR’ on the four-digit display for three seconds. The controller will check the sensor connected to ‘TS1’ for a short or an open. It will display ‘CKT1’ on the four-digit display for three seconds. If the sensor fails, the controller will display the alarm ‘STSA’ on the four-digit display and go to safety mode for a failed suction sensor. If the sensor passes, it will display ‘OKT1’ on the four-digit display for three seconds. The controller will check the sensor connected to ‘TS2’ for a short or an open. It will display ‘CKT2’ on the four-digit display for three seconds. If the sensor fails, the controller will display the alarm ‘ATSA’ on the four-digit display and go to safety mode for a failed air sensor. If the sensor passes, it will display ‘OKT2’ on the four-digit display for three seconds. The controller will check the sensor connected to ‘TS3’ for a short or an open. It will display ‘CKT3’ on the four-digit display for three seconds. If the sensor fails, it will display the alarm ‘CTSA’ on the four-digit display and go to safety mode for a failed coil temperature sensor. If the sensor passes, it will display ‘OKT3’ on the four-digit display for three seconds. If all sensors pass, the controller will display ‘CKFH’ on the four-digit display for six seconds.

The controller will not go into defrost during the preceding start up procedure. It will check the number of defrosts per day (DFPD) and time_of_day (HOUR, MIN). If it is time for the controller to be in defrost, it will start in DEFROST mode. If not, the controller will start in COOL(REFR) mode after fan delay.

The set points are stored in EEPROM (Electrically Erasable Programmable Read Only Memory). Batteries are not required to store the new set points. If power is lost, the set points which were in the controller at that time will be used when power is restored.

OFF MODE (OFF)

The controller starts in OFF mode by fully closing the valve. The controller will keep the valve closed for the minimum OFF Time (MOTM) in order to keep the compressor in pumpdown or off for a minimum amount of time.When the room temperature reaches the cut-in set point (room temperature set point “RMSP” plus the temperature difference set point “ADIF”), the controller goes to COOL mode (REFR).

If a scheduled defrost scheme is selected, while the controller is in OFF mode, it is constantly checking the number of defrosts per day and the time_of_day and calculating the time for defrost. When the time_of_day is right for a defrost, it will immediately go into DEFROST mode right after the current OFF mode.

If the demand defrost scheme is selected, defrost will be checked and initiated only during the COOL mode.

After the Minimum OFF Time is timed out and the room temperature reaches the Cut-In temperature, the controller will go into COOL mode(REFR).

While in OFF MODE, the four-digit display on Master will show ‘OFF’ for three seconds, ‘RMTP’ for two seconds, and the numerical display of the room temperature for five seconds. The four-digit display on controllers without an air temperature sensor will show ‘OFF’.

COOL MODE (REFR)

The controller starts COOL mode by opening the valve. The condensing unit will start by a suction line low pressure control cut-in. The electric expansion valve is modulated by the controller so that a preprogrammed superheat set point is maintained during the refrigeration process. Actual superheat is the temperature difference of the evaporator outlet and the evaporating temperature converted from the reading of the presssure transducer, or T set point. Meanwhile, the controller reads also the room air temperature TS2. When the room temperature is below the room temperature set point (pre-set to -10 oF for low temp), it goes back to OFF mode. All the time that the controller is in COOL mode, it is constantly checking the criteria to determine if a defrost should be initiated. It will immediately go into DEFROST mode (DEFR) when defrost criteria are met.

If the suction pressure is above the maximum operating pressure set point (MOP), the valve will modulate to control the pressure at or below the maximum operating pressure set point (MOP). When the operating suction

. The controller will keep modulating the valve so the superheat will equal the superheat

out-Tsat

pressure is lower than MOP, it will go back to superheat control. Suction pressure is used to calculate saturated temperature (TSAT).

If the suction pressure is below the Minimum pressure set point (MNPR), the valve will close and the control signal to the external relay will be turned off. It will resume normal operation when the pressure is above the Minimum pressure set point.

While in COOL MODE, the four-digit display on Master will show ‘REFR’ for three seconds, ‘RMSP’ for two seconds, and the numerical display of the room temperature for five seconds. The four-digit display on controllers without an air temperature sensor will show ‘REFR’.

DEFROST MODE (DEFR)

There are two methods to determine if a defrost will be initiated for the Master Controller: scheduled defrost and demand defrost. If the parameter “DINM” = “DEMD” and the number of defrosts per day ‘DFPD’ is set to 0, the controller will do the demand defrost by default. If the parameter “DINM” = “SCHD” and the number of defrosts per day ‘DFPD’ is set from 1 to 8, the controller will do the scheduled defrost.

Scheduled Defrost

The following is the description of the scheduled defrost.

The time_of_day is really an elapsed counter that counts the number of minutes that have passed. An elapsed count of 0 is 12:00 AM. The count goes up to 1439 which corresponds to 11:59 PM. The counter then will reset to 0.

The time of day will be kept as long as input power is connected. If input power is turned off, then back on, the time of day will be reset to 0 which corresponds to 12:00 AM.

The first defrost start time is an elapsed time of 0 (12:00 AM). The subsequent defrost start times are determined by adding the number of minutes between each defrost to the previous start time until there is a defrost start time for each defrost per day. The number of minutes between each defrost is determined by taking 1440 / number of defrosts per day as set up by the ‘DFPD’ set point.

When starting an electric defrost, FAN relay is de-energized to turn off the fans. The controller waits for five seconds, then the DEFROST relay is energized to start a defrost.

When starting a reverse cycle defrost, the FAN relay is de-energized to turn off the fans while, at the same time, COMPRESSOR relay is de-energized to turn off the compressor. There is a 10 second delay before the DEFROST relay is energized to switch the four-way reverse valve. Then there is a 30 second waiting period for pressure equalizing. Afterward, COMPRESSOR relay is energized to turn the compressor. Hot gas will be reversed to flow to the evaporator while the electric expansion valve is modulated to start a defrost.

The controllers use the coil sensor ‘TS3’ as the defrost termination sensor. When this temperature gets above the preprogrammed Defrost Termination Set Point (DTSP) before the preprogrammed Maximum Defrost Time (MXDT), the defrost will terminate. Otherwise, it will be terminated when the Maximum Defrost Time (MXDT) times out.

While in DEFROST MODE, the four-digit display will be ‘DEFR’ for three seconds, ‘DTTP’ for three seconds, and the numerical display of the temperature reading from sensor TS3 for three seconds.

Demand Defrost

When “DINM” = “DEMD” and ‘DFPD’ is set to ‘0’, the controller will initiate a demand defrost. The controller will not go to ‘DEFROST MODE’ until a heavy frost accumulation is in the evaporator coil. When frost is built up in the evaporator, it will block the air flowing through the evaporator coil and reduce the heat transfer area. It will also decrease the evaporating temperature, which, in turn, increases probability of frosting. A demand defrost scheme to detect the frost build-up and the criteria to start defrost are programmed in the Master Controller. Unlike scheduled defrost, the Master Controller 2.0 with demand defrost is really an energy saver. If no selection is made, the controller will automatically select demand defrost when the power is applied to the controller. The defrost procedure is the same as described for the scheduled defrost.

After selecting the demand defrost, if the elapsed time since the last defrost has been a selectable time (INTV) from 8 hours (480) to 72 hours(4320), the Master Controller 2.0 will go into defrost to ensure a proper oil return.

Manual Defrost

The controller allows manually-initiated defrost when needed. The manual defrost will be disabled if the evaporator inlet sensor detects the temperature higher than the defrost termination temperature. Operation of the manual defrost will be discussed in a later section.

COIL DRAIN MODE (DRAN)

The controller automatically goes into COIL DRAIN whenever a defrost is terminated. The controller stays in this mode for the preprogrammed ‘DRIP TIME’. When this time is completed the controller opens the expansion valve and goes into FAN DELAY mode (FNDL).

While in COIL DRAIN MODE, the four-digit display on the controller will show ‘DRAN’ for five seconds, ‘RMTP’ for three seconds, and the numerical display of the room temperature for three seconds. The four-digit display on controllers without an air temperature sensor will show ‘DRAN’.

FAN DELAY MODE (FNDL)

The controller will pull down the temperature of the evaporator without the fans on until one of the following occurs: The FAN DELAY TIME of five minutes times out or the fan cut-in sensor’s temperature (FDTP) TS1 goes below the FAN DELAY TEMPERATURE of 30 Deg F. The controller will then go into COOL mode.

While in FAN DELAY MODE, the four-digit display will be ‘FNDL’ for three seconds, ‘FDTP’ for three seconds, and the numerical display of the temperature reading from sensor TS1 for three seconds.

SAFETY MODE

When an alarm occurs, such as a sensor failure or a communication alarm, the controller will go into ‘SAFETY MODE’. SAFETY MODE provides minimum refrigeration to the refrigerated room before the corrective action is taken and the alarm is cleared. The system will do the following in Safety Mode:

• Pressure transducer alarm (PRSA) o Cool mode

 Valve open for the minimum compressor run time  Valve closed for the minimum compressor off time  Keep doing above cycle until alarm goes away  Ignores maximum pressure control mode

• Outlet sensor alarm (STSA)

o Cool mode

 Valve open for the minimum compressor run time  Close valve for the minimum compressor off time  Keep doing above cycle until alarm goes away.

o Fan delay mode

 Lets fan delay time out (five minutes)

o Defrost Mode

 If this alarm and defrost term temp sensor alarm, reverse cycel defrost will last only

three minutes with valve open;

 If this alarm and defrost term temp sensor alarm, electric defrost will last only ten

minutes with valve closed.

• Room temp sensor alarm (ATSA) o Cool Mode

 Run on superheat control for the minimum compressor run time  Close valve for the minimum compressor off time  Keep doing above cycle until alarm goes away.

• Low superheat alarm (LOSH)

o Close valve and wait for alarm to go away.

• High Room Temperature Alarm (HITA)

The ‘high room temperature alarm’ occurs when the room temperature is above the preprogrammed ‘HIGH TEMPERATURE ALARM’ for a preprogrammed number of minutes. The alarm is cleared when the room temperature is less than the ‘HIGH TEMPERATURE ALARM’ set point.

• Low Room Temperature Alarm (LOTA)

The ‘low room temperature alarm’ occurs when the room temperature is below the preprogrammed ‘LOW TEMPERATURE ALARM’ for a preprogrammed number of minutes. The alarm is cleared when the room temperature is above the ‘LOW TEMPERATURE ALARM’ set point.

• Defrost term temp sensor alarm (CTSA) o Defrost mode

 Open valve until alarm goes away or defrost terminates.  If this alarm and outlet temp sensor alarm, defrost will last only three minutes.  Use outlet sensor for defrost temperature termination

• Communication alarm (COMA)

o For Alternating mode, (ALTN) go to standalone mode. o For Synchronous mode, (SYNC)

 Cool mode

• Run on superheat control for the minimum compressor run time

• Close valve for the minimum compressor off time

• Keep doing above cycle until alarm goes away.

 Pumpdown Mode

• Wait until pump down time times out.

 Drip Mode

• Wait until Drip time times out.

 Defrost Mode

• Valve will close when defrost termination temperature meets its set point if reverse cycle defrost. Valve will close at all time if electric defrost. It will then wait the full defrost time for other evaporators to defrost..

• If in demand defrost mode, defaults to three defrosts per day.

Multiple Evaporator Configuration

The Master Controller 2.0 can be configured with 0 to 7 other controllers. Each controller is appointed a static I/P address at the factory for communication and sequence of operation. The evaporators are piped together to one condensing unit. The room temperature sensor is mounted on any of the controllers. All controllers can have a room temperature sensor connected for better control. All evaporators have a pressure transducer, outlet sensor and coil sensor. All controllers will communicate with each other to share the room temperature reading and the coil temperature reading. All controllers can modulate its electric expansion valve independently .

• The communication cable is a CAT/5E cable, up to 330 feet.

• Communication for peer to peer control are connected to the RJ-45 connector.

BOND CONTROLLERS FROM FRONT PANEL

• Connect to Ethernet switch or router only the controllers that you want to bond.

• On any controller, using the left and right buttons, go to Manual Mode (MNMD).

• Press ‘ENTER’, display will show Password (PSWD), press ‘ENTER’

• Using the left, right, up and down buttons enter ‘0002’ and hold ‘ENTER’ button until display shows one

of the manual modes.

• Using the up and down buttons, go to ‘BOND’, press ‘ENTER’, display will show ‘ITBD’ (initialize bond).

• Press and hold the ‘ENTER’ button until display shows ‘MNMD’. After about 5 seconds, all controllers

will reset. They are then bonded.

PEER TO PEER MODE

When power is turned on, that controller will initialize itself by closing the valve. A ‘ROOM TEMPERATURE’ sensor is needed to be connected to only one Controller. A ‘ROOM TEMPERATURE ALARM’ is set only if none of the controllers have a good air temperature sensor connected. If it does not have a room temperature sensor connected, it will put itself in ‘COOL’ mode and wait to get the room temperature from another controller. If it does not receive any command within a minute, it will set the ‘communication alarm’ and then run in ‘SAFETY

MODE’ as described previously. The ‘communication alarm’ clears when it receives any command from that controller. The controllers switch between ‘COOL’ mode and ‘OFF’ mode based on the warmest temperature reading from all controllers that have a room temperature sensor.

If any controller decides to go in defrost, all controllers will then go into defrost. If any controller decides to go in drain mode, all controllers will then go into drain mode. If any controller decides to go in fan delay mode, all controllers will then go into fan delay mode If there is a communication alarm at any controller, then the controller will go into defrost as a scheduled

defrost that will terminate on time only.

ALTERNATING MODE

The controller can be configured as an alternating system for dual single-evaporator refrigeration units to provide redundancy of a refrigerated cold room. Once the network is set up, a CAT/5E cable can be connected between the 2 controllers or a switch/router, connected to the RJ-45 connector. When the alternating mode is selected, the dual refrigeration units will start pulling down box temperature to the cut-out set point then both go into OFF MODE(OFF). When the box temperature rises up to cut-in temperature, the one of the units will come on while the other stays off. The other evaporator will perform the refrigeration in next cooling cycle.

IMPORTANT NOTE:

In the controller, the parameter of “DFMD” has to be set for proper method of defrost. “DFMD = ELEC” is for regular electric defrost; “DFMD = RCD” is for regular reverse cycle defrost;

Definition of On-Board Symbols

STATUS, DEFAULT AND READING DISPLAY

When the on-board green light is on, the compressor relay is energized. W hen the green light is blinking, the room temperature sensor is satisfied, but waiting for the minimum off timer or minimum run timer to time out. When the red light is on, there is a critical alarm. When the amber light is on, there is a non-critical alarm.

The status and the digital data are displayed on the onboard four-digit LED display. Below is a list of the

parameters of the operational status.

Onboard Four-Digit Display Description

STUP Indicates the status of Start Up Mode CKFN Check fan working status CKP1 Check pressure transducer OKP1 Indicates the pressure transducer is working as it should CKT1 Check sensor TS1, the suction/fan cut-in temperature sensor OKT1 Indicates the TS1 is working as it should CKT2 Check sensor TS2, the room temperature sensor OKT2 Indicates the TS2 is working CKT3 Check sensor TS3, the coil temperature sensor OKT3 Indicates the TS3 is working CKFH Indicates all sensors are OK FNDL Indicates FAN DELAY MODE FDTP Actual TS1 value in FAN DELAY COOL Indicates COOL MODE OFF Indicates OFF MODE PMDN Indicates PUMPDOWN MODE before an electric defrost DEFR Indicates DEFROST MODE DRAN Indicates COIL DRAIN MODE DFTP Inlet sensor TS3 value in DEFROST MODE

A list of the parameters that can be displayed and/or changed is shown below when access to the default settings is needed. This access is usually done by a trained technician.

VARIABLES OnboardDisplay

Description RMTP Room Temperature SUPH Superheat

PRES Suction Pressure Reading

TSUC Suction Temperature Reading

TSAT Saturated Temperature

TCOI Coil Temperature VALV Expansion Valve Position

STAT

Status REFR/OFF/DEFRODT/DRAIN/FAN DELAY ALCM ON

RLDF RLFN ALAU

Defrost Relay ON/OFF

Fan Relay ON/OFF

AUX Relay ON/OFF

D1ST DIGITAL Input 1 Status D2ST DIGITAL Input 2 Status D3ST DIGITAL Input 3 Status

IPQ1 1ST Quadrant of IP Address IPQ2 2nd Quadrant of IP Address IPQ3 3rd Quadrant of IP Address

IPQ4 4th Quadrant of IP Address NET1 1ST Quadrant of Subnet Mask NET2 2nd Quadrant of Subnet Mask NET3 3rd Quadrant of Subnet Mask NET4 4th Quadrant of Subnet Mask

FWRV Firmware Version V3.98

MANUAL MODES

MCTL MANUAL STATUS MVLV MANUAL VALVE

CLAL CLEAR ALARM

BOND BOND CONTROLLERS

The Following list indicates parameter valures of the controller and may be changed to customize the refrigeration system.

TYPICAL SET POINTS FOR AMC CONTROLLER 2.0

SETPOINT

PARAMETERS

REFT R-404a,R-22 404A 404A 404A 404A VTYP

SHSP Superheat Set Point 10 10 10 10

MOP Max Suction Pressure Setpoint 55 80 55 80

RMSP Room Air Setpoint -10 35 -10 35

ADIF Room Air Differential 5 5 5 5

MRTM

MOTM

MNPR Minimum Suction Pressure Setpoint 5 15 5 15

T4TP

REL4

CYCF

DINM

DFPD

DFMD

INTV Maximum Time Between Defrost 720 min 720 min 720 min 720 min PMDN Pump Down Time Before Defrost 1 1 1 1 CYCD

DTSP Defrost Termination Setpoint 50F 45F 50F 50F MXDT Maximum Defrost Time 35 min 35 min 35 min 35 min DRAN Drain Time 2 min 2 min 2 min 2 min

MEVM

ALSP Air DIFF. To Leave Alternating Mode 5 5 5 5

HITA HIGH Air Temperature ALARM Offset 20 20 20 20

LOTA LOW Air Temperature ALARM Offset 10 10 10 10

HITD High Air Temp DELAY 45 min 45 min 45 min 45 min

DI1M

DI1S

DI2M

DI2S

DI3M

DI3S

RMT2 Room TEMP Sensor #2 -5 42 -5 42

HOUR Hour of Day N/A N/A N/A N/A

MIN Minute of Day N/A N/A N/A N/A

DESCRIPTIONS Freezer Cooler

Valve Type MECH/SERB/CUST

Minimum RUN Time Minimum OFF Time

AUX Temp Functionality DISA/T4RT/4CL AUX Relay Functionality ALMR/2COMP/2FAN/2SPR/PEDR FAN Cycle Mode ON/CYCL CYCL CYCL Defrost Initiate Mode DEMD/SCHD SCHD SCHD DEMD SCHD # Of DEFROST per day Defrost Mode ELEC/RCD

Defrost Heater Cycle Mode ON/CYCL CYCL CYCL ON ON

Multiple Evap Mode SYNC/ALTN

DIGITAL INPUT 1 MODE DISA/SOFF/DOOR/2NRT/DFLO/DFIL DIGITAL INPUT 1 STATE OPEN/ CLOSE DIGITAL INPUT 2 MODE DISA/SOFF/DOOR/2NRT/DFLO/DFIL DIGITAL INPUT 2 STATE OPEN/CLOSE DIGITAL INPUT 3 MODE DISA/SOFF/DOOR/2NRT/DFLO/DFIL DIGITAL INPUT 3 STATE OPEN/CLOSE

Air/Electric Defrost

SERB SERB SERB SERB

2 2 2 2 2 2 2 2

DISA DISA DISA DISA

ALMR ALMR ALMR ALMR

4 2 0 3

ELEC ELEC RCD RCD

SYNC SYNC SYNC SYNC

SOFF SOFF SOFF SOFF

CLOS CLOS CLOS CLOS

DISA DISA DISA DISA

CLOS CLOS CLOS CLOS

DISA DISA DISA DISA

CLOS CLOS CLOS CLOS

Reverse Cycle Defrost

Freezer Cooler

CYCL CYCL

ALARM DISPLAY

Any alarm will cause alarm relay to switch. All alarms have a distinct display shown on the four-digit display on the controller. The red LED will be on for a pressure or suction temperature sensor alarm and the amber LED will on for all other alarms. Multiple alarms can exist. There is a priority as to which alarm will be displayed before another.

Onboard 4 Digit Display

ALARMS

PRSA PRESSURE SENSOR ALARM 1 STSA SUCTION TEMP SENSOR ALARM 2 ATSA AIT TEMP SENSOR ALARM 3 CTSA COIL TEMP SENSOR ALARM 4 ATSA AUX TEMP SENSOR ALARM 5 LOSH LOW SUPERHEAT ALARM 6 HITA HIGH TEMPERATURE ALARM 7 LOTA LOW TEMPERATURE ALARM 7 LPRA LOW PRESSURE ALARM 7 XTA1 EXTERMAL ALARM/ DIGITAL INPUT 1 8 XTA2 EXTERMAL ALARM/ DIGITAL INPUT 2 8 XTA3 EXTERMAL ALARM/ DIGITAL INPUT 3 8 DROA DOOR OPEN ALARM 9 COMA COMMUNICATION ALARM 10

Description

PRIORITY

Setting Parameters By On-Board Pushbuttons

There are two levels for programming the controllers with the four-digit display and six pushbuttons. The first level (User’s Level) will enable the USER to set the room temperature set point ‘RMSP’; the second level (Technician’s Level) allows access to the other parameters as described above.

User’s Level Press the right or left button until ‘STPT’ (Set point) is displayed. Press the ‘ENTER’

button. If ‘PSWD’ (Password) is displayed, press the ‘ENTER’ button again. The display should read ‘0000’ with the 0 on the right blinking. Enter the password ‘0001’ by using the up and down buttons to increment or decrement the blinking digit, and the right or left buttons to move the blinking digit to the next digit. When the display reads ‘1111’, press and hold the ‘ENTER’ button (about 3 seconds) until ‘RMSP’ (room set point’ is displayed. Press the ‘ENTER’ button to display the value for ‘RMSP’. If you want to change the value, press and hold the ‘ENTER’ button until the right digit starts blinking (about 3 seconds). Use the up and down buttons to increment or decrement the value. Use the right and left buttons to change the digit that is blinking. When the value that is wanted is displayed, press and hold the ‘ENTER’ button until the digit stops blinking (about 3 seconds). At any time, pressing the ‘BACK’ button will escape to the step before.

TECHNICIAN’s Level Press the right or left button until ‘STPT’ (Set point) is displayed. Press the ‘ENTER’

button. If ‘PSWD’ (Password) is displayed, press the ‘ENTER’ button again. The display should read ‘0000’ with the 0 on the right blinking. Enter the password ‘0002’ by using the up and down buttons to increment or decrement the blinking digit, and the right or left buttons to move the blinking digit to the next digit. When the display reads ‘0002’, press and hold the ‘ENTER’ button (about 3 seconds) until a set point’ is displayed. Use the up and down buttons to get to the set point that is wanted. Press the ‘ENTER’ button to display the value for that set point. If you want to change the

value, press and hold the ‘ENTER’ button until the right digit starts blinking (about 3 seconds). Use the up and down buttons to increment or decrement the value. Use the right and left buttons to change the digit that is blinking. When the value that is wanted is displayed, press and hold the ‘ENTER’ button until the digit stops blinking (about 3 seconds). At any time, pressing the ‘BACK’ button will escape to the step before.

MANUAL VALVE Press the right or left button until ‘MNMD’ (Manual Mode) is displayed. Press the

‘ENTER’ button. If ‘PSWD’ (Password) is displayed, press the ‘ENTER’ button again. The display should read ‘0000’ with the 0 on the right blinking. Enter the password ‘0002’ by using the up and down buttons to increment or decrement the blinking digit, and the right or left buttons to move the blinking digit to the next digit. When the display reads ‘0002’, press and hold the ‘ENTER’ button (about 3 seconds) until a manual mode is displayed. Use the up and down buttons to get to ‘MVLV’ (manual valve). Press the ‘ENTER’ button to display the value for the valve position. Use the up and down buttons to increment or decrement the percentage for the valve to be open. Use the right and left buttons to change the digit that is blinking. At any time, pressing the ‘BACK’ button will escape manual valve mode and go back to auto mode. If no buttons are pressed for 1 hour, the controller will go back to auto mode.

CLEAR ALARM Press the right or left button until ‘MNMD’ (Manual Mode) is displayed. Press the

‘ENTER’ button. If ‘PSWD’ (Password) is displayed, press the ‘ENTER’ button again. The display should read ‘0000’ with the 0 on the right blinking. Enter the password ‘0002’ by using the up and down buttons to increment or decrement the blinking digit, and the right or left buttons to move the blinking digit to the next digit. When the display reads ‘0002’, press and hold the ‘ENTER’ button (about 3 seconds) until a manual mode is displayed. Use the up and down buttons to get to ‘ALST’ (alarm status). Press the ‘ENTER’ button and the display will show ‘CLAL’ (clear alarm). Press and hold the ‘ENTER’ button until the display changes. The alarms have cleared. At any time, pressing the ‘BACK’ button will escape this mode the previous step.

MANUAL DEFROST Press the right or left button until ‘MNMD’ (Manual Mode) is displayed. Press the

‘ENTER’ button. If ‘PSWD’ (Password) is displayed, press the ‘ENTER’ button again. The display should read ‘0000’ with the 0 on the right blinking. Enter the password ‘0002’ by using the up and down buttons to increment or decrement the blinking digit, and the right or left buttons to move the blinking digit to the next digit. When the display reads ‘0002’, press and hold the ‘ENTER’ button (about 3 seconds) until a manual mode is displayed. Use the up and down buttons to get to ‘MCTL’ (manual control). Press the ‘ENTER’ button to display the mode that the controller is in. To change the mode, press and hold the ‘ENTER’ button (about 3 seconds) until the display changes to the next mode. If the controller was in ‘COOL’ or ‘OFF’, it will go to ‘DEFR’. If the controller was in ‘DEFR’, it will go to ‘DRAN’. If the controller was in ‘DRAN’, it will go to ‘FNDL’. If the controller was in ‘FNDL’, it will go to ‘COOL’. At any time, pressing the ‘BACK’ button will escape manual valve mode and go back to auto mode.

BOND CNTRLRS Connect the controllers that need to communicate with each other using the RJ-45

connector of the controller to an ethernet switch or router. If there are just 2 controllers, you can connect them directly, without the ethernet switch or router. Disconnect any

other controller that is not going to communicate with this group of controllers.

On any of the controllers, press the right or left button until ‘MNMD’ (Manual Mode) is displayed. Press the ‘ENTER’ button. If ‘PSWD’ (Password) is displayed, press the ‘ENTER’ button again. The display should read ‘0000’ with the 0 on the right blinking. Enter the password ‘0002’ by using the up and down buttons to increment or decrement the blinking digit, and the right or left buttons to move the blinking digit to the next digit. When the display reads ‘0002’, press and hold the ‘ENTER’ button (about 3 seconds) until a manual mode is displayed. Use the up and down buttons to get to ‘BOND’ (bond controllers). Press the ‘ENTER’ button and the display will show ‘INBD’ (initiate bonding). Press and hold the ‘ENTER’ button until the display changes. After 3 to 5 seconds, all connected controllers will reset. The bonding process is complete. At any time, pressing the ‘BACK’ button will escape this mode the previous step.

Temperature Sensors

of the evaporator as shown in Figure 4. These sensors are interchangeable.

The application range of the temperature sensors used for this controller is -60oF to +150oF. If the sensor detects a temperature out of the range, an alarm will show on the controller display.

Three temperature sensors are used in the Master Controller 2.0 refrigeration system. They are the room temperature return air sensor, the evaporator defrost termination temperature surface sensor and the evaporator outlet (suction line) temperature surface sensor. All sensors are solid state devices with the same characteristics that change electrical resistance in response to a change in temperature.

The room temperature sensor is factory-mounted on the lower back of the

evaporator at the drain pan. This placement avoids heat from defrost heaters

and lights and still allows a good air stream over the sensor. Figure 3 shows a

typical mounting of the room temperature sensor.

The defrost termination sensor is mounted on one of the distributor tubes close

the coil end plate. The outlet sensor is mounted on the suction line at the outlet

SENSOR SERVICE INSTRUCTIONS

Care must be taken when brazing the suction line at the evaporator. The outlet sensor must be taken out before brazing. After brazing, fasten the sensor with the metal strap provided. Make sure the sensor is tight and has good contact with the suction line.

The temperature sensor cannot be repaired. Using the measurements in Chart A below, you can determine if they are functioning correctly. If the sensors are found out of tolerance, they should be replaced.

As mentioned above, the temperature sensor changes

electrical resistance in response to temperature changes.

EVAP OUT FAN DELAY TEMP SENSOR

SUCTION LINE

PRESSURE

TRANSDUCER

Disconnect the sensor from the controller, check the temperature at the sensor location, then check and record the resistance

6" TO 10"

through the temperature sensor.

Procedures to check temperature sensor tolerance with ice water:

1. Use a cup of water with well-stirred ice. The water temperature should be an even 32°F.

2. Submerge the room temperature sensor (TS2) into the water while the Master Controller 2.0 is normally operating. Check the display for the value. If the sensor shows 32°F, it is working properly.

3. Press the right or left buttons until the display shows the name of one of the variables. Press the up or down buttons until the display reads ‘TCOI’, the defrost termination sensor (TS3). Press the ‘ENTER’ button to display the value. Submerge the sensor into the water. Check the display for the value. If the sensor shows 32°F, it is working properly.

4. Scroll down the display to “TSUC”, the outlet sensor (TS1) value.

5. Submerge the outlet sensor into the water. Check the display for the value. Again, if the sensor shows 32°F, it is working properly.

Compare the temperature and resistance to Chart A.

Figure 3

DEFROST TERMINATION

TEMP SENSOR

Figure 4

Chart A. Temperature/Resistance Characteristics (-50 to 80 oF)

Temp. oF Temp. oC ohms*1k Temp. oF Temp. oC ohms*1k

-50 -45.6 43.45 15 -9.4 7.579

-40 -40.0 32.31 20 -6.7 6.731

-35 -37.2 27.96 25 -3.9 5.993

-30 -34.4 24.27 30 -1.1 5.349

-25 -31.7 21.13

-20 -28.9 18.43 35 1.7 4.781

-15 -26.1 16.12 40 4.4 4.281

-10 -23.3 14.13 50 10.0 3.454

-5 -20.6 12.42 60 15.6 2.805

0 -17.8 10.94 70 21.1 2.294

5 -15.0 9.651 80 26.7 1.888

10 -12.2 8.544

32 0 5.123

NOTE: Use resistance at 32oF for sensor checking.

Pressure Transducer

Your Master Controller 2.0 will be equipped with one of two types of pressure transducer (PT). The difference is in the color of sensor wires as noted below:

New PT (19-14226, 19-14223) OLD PT (19-13955, 19-14092) Description

RED BLACK +VDC (+5) GREEN WHITE SIGNAL (sig) BLACK GREEN GROUND (5-)

The GROUND is connected to terminal ‘5-‘ on the board. The SIGNAL lead is connected to terminal ‘sig’ on the board. The +VDC lead is connected to terminal ‘5+’ on the board. Chart B shows the characteristics of the pressure transducer. NOTE: The pressure transducer cannot be repaired but replaced only.

Chart B. Pressure Sensor Simulation Values ( 0 to 150 PSIA)

Bar PSIA

0 0

0.69 10

1.379 20

2.069 30

2.758 40

3.448 50

4.137 60

4.827 70

5.516 80

6.206 90

6.895 100

7.585 110

8.274 120

PSIG

-14.6

-4.6

5.4

15.4

25.4

35.4

45.4

55.4

65.4

75.4

85.4

95.4

105.4

(Signal to Ground)

0.509

0.784

1.058

1.332

1.587

1.862

2.136

2.391

2.665

2.920

3.194

3.469

3.724

Charging the Master Controller 2.0 Refrigeration System

Note: If you are a first time installer of a Master Controller 2.0 system, please call Master-Bilt for on-phone training.

Since the system is designed with free floating head control, the head pressure control valve is not installed in this type of system. Therefore, the compressor operates at its highest EER value.

During initial pull down, after primary charge while the system is running, a large evaporator superheat is built up. The electric expansion valve is then open all the way. If the system is charged full sight glass during this period, the system is already overcharged.

Note: The liquid line size is determined by conventional piping practices for air and electric defrost. For reverse cycle defrost, the liquid line must be selected by choosing the liquid line one nominal step larger than the conventional approach. For example: for an evaporating temperature =

-20ºF, refrigerant R-404A, and a capacity of 20,000 Btuh, the conventional tables will suggest a liquid line size of ½” OD. When utilizing the reverse cycle feature of the Master Controller, the liquid line size should be 5/8” OD. When utilizing the electric or air defrost scheme, there is no need to make the line larger.

All suction lines may be chosen by conventional practices. Please note the “stubs” at both the evaporator and condensing unit do no necessarily mean that this is the correct size for your application.

Calculation of estimated amount of working refrigerant: The amount of working refrigerant can be estimated by the following formula:

Tons of cooling capacity x 4.5 LBS/Ton + Full Liquid Line Charge between Evaporator and Condenisng Unit

For example, a system of 12,000 BTUH @ -20F suction, 50 ft 1/2” liquid line run, R404A, 100F Liquid, the working amount of refrigerant is: 1 x 4.5 + 6.5 x 50/100 = 7.75 LBS R404A. The actual charge should be

approximately this working amount of refrigerant.

Weight of Refrigerant in LBS per 100 ft of Liquid Line:

The recommended charging procedures are:

Liquid Line Size, Inch

3/8 R22

1 /2 R22

5/8 R22

7/8 R22

(1) Charge the system by weighing exact amount of refrigerant specified by Master-Bilt for the unit. Or,

Refrigerant Lbs of Refrigerant

4.0

R404A

3.5

7.5

6.5

12.0

10.5

24.5

21.0

(2) Charge 50% of the liquid receiver (if provided) rated holding capacity. Let the system run through the

pull down period until room temperature is closely reached, then gradually add refrigerant until actual superheat “SUPH” on board is approaching superheat setpoint “SHSP”. Bubbles may be seen in the sight glass.

(3) In a reverse cycle defrost system, there may not be a liquid receiver. Charge the system the working

amount of refrigerant calculated above. Let the system run through the pull down period until room temperature is closely reached. Then gradually add refrigerant until actual superheat “SUPH” on board is approaching superheat setpoint “SHSP”. Bubbles may be seen in the sight glass.

How to diagnose an overcharged system:

An overcharged system will not operate properly.

• First, be sure that system is not leaking

• Compressor may be short cycling

• Frost building up on compressor suction section, suction filter or service valve

• Low superheat alarm appears on the controller display constantly

• Head pressure cut-out during defrsot for a reverse cycle defrost system

Solution:

Taking some refrigerant out of the system until on-board actual superheat “SUPH” is observed approaching superheat setpoint “SHSP”.

Technical Notes

•

With the optional alarm relay the external temperature and alarm indicator should be connected to “C” (common) and “NC” (normal close) terminals. The alarm does not indicate what causes the alarm. To find out what has caused the alarm, check the onboard four-digit display for alarm codes and refer to the diagnosis chart for corrective action. Thermostat wiring can be used for connection.

• Defrost termination set point (DTSP) can be also set up to 80oF. When setting the defrost termination temperature, make sure that the frost is free after each defrost. Also make adjustments to the maximum defrost duration when necessary.

• The superheat of each application can be set by the customer. Superheat 10-15oF is recommended for winter operation, superheat 5-10oF for summer.

• Always clear the “LOSH”, “HITA” and “LOTA” alarms after corrective action is taken. The sensor and communication alarms cannot be cleared unless they are corrected.

• Cat5/e communication cable should be rated 300 V 80oC or higher. If the wire is rated lower than 300 V, a separate conduit must be used for communication cables.

•

Follow the instructions in the Master-Bilt Condensing Unit and Refrigeration System Installation & Operation Manual to perform the final check up before charging and starting up the system. Always refer to this service manual, make sure all steps are understood. Don’t hesitate to call Master-Bilt Customer Service Department at 800-684-8988 for technical assistance.

REVERSE CYCLE DEFROST

General Information

Master-Bilt’s patented (U.S. patent no. 7,073,344) reverse cycle defrost is a standard feature on Master Controller-equipped refrigeration systems. A reverse cycle valve is already factory-installed on the condensing unit. The valve’s primary function is to reverse the direction of the refrigerant flow during defrost. When the Master Controller’s demand defrost determines that a defrost is necessary, the reverse cycle valve is activated and the high temperature refrigerant flow is reversed.

Under the normal refrigeration cycle, the refrigerant flow is the same as traditional refrigeration modes. During the defrost mode, the refrigerant flow is reversed back through the evaporator coil heating it from the inside-out along its entire length and completely eliminating frost buildup (see figure 5 below).

Figure 5

Advantages

Reverse cycle technology offers several significant advantages:

• An up to 80% reduction in defrost energy usage. This savings, coupled with that from the demand defrost feature, dramatically reduces energy consumption.

• Eliminates many mechanical parts

• Reduces cost of evaporator, installation and wiring

• Reduces defrost time

• No significant increase in freezer room temperature

• No noticeable increase in product temperature

Factory-Installed Parts

A 4-way reversing valve, operating at 24 VAC, is installed in a reverse cycle defrost unit. A transformer is also installed in the master evaporator to supply 24VAC to the 4-way reversing valve.

Eliminated Parts

The Master-Bilt Reverse cycle’s unique technology, coupled with the bi-flow electric expansion valve, eliminates the need for:

• Defrost heaters

• Head pressure control valves

• Check valves and expansion valves at the condenser that are normally necessary in traditional hot gas

defrost systems

• By-pass valves

• Liquid line solenoid valves

• Receiver tanks (except in B-series condensing units 6 HP and up)

• Sight glasses

Removing these components reduces the cost of the evaporator itself and saves on installation and wiring.

Defrost Time

Defrost time is greatly lessened with the reverse cycle option. The average time using electric defrost heaters is 20-30 minutes but reverse cycle performs a completely “clean” defrost typically in 3 – 5 minutes for freezers and 11/2 – 2 minutes for coolers. Because the defrost is so rapid, there is no noticeable increase in freezer room temperature and the product temperature rise is also significantly less. Reverse cycle defrost, combined with demand defrost, assures the evaporator receives the number of complete defrosts needed at the necessary times to prevent iced evaporators while assuring the protection of the valued product being stored.

Charging a Master Controller 2.0 System Equipped with Reverse Cycle Defrost

Note: If you are a first time installer of a Master Controller 2.0 system, please call Master-Bilt for on-phone training.

Please refer to Page 21: Charging the Master Controller 2.0 Refrigeration System

Due to the reversing of the refrigerant flow, it is recommended that the refrigeration liquid line piping also be insulated to prevent condensation drips between the condensing unit and the evaporator coil.

ELECTRIC WIRING

WARNING

Please make sure to turn all power off before servicing electrical equipment. Always use a qualified and trained technician. If you are the technician and a first-time installer of a Master Controller 2.0 system, call our service department at 800-684-8988 for free training and support.

The field wiring for a Master Controller 2.0 refrigeration system includes the power supply to the

condensing unit, the evaporator (fans, heaters and controller) and the communication cables between master and slaves. Thermostat wiring may be used for four-way reversing valve power supply since it is 24 VAC.

TYPICAL WIRING DIAGRAM (AIR DEFROST)

N.O.

TYPICAL WIRING DIAGRAM (REVERSE CYCLE DEFROST)

N.O.

TYPICAL WIRING DIAGRAM (ELECTRIC DEFROST)

Note: For feature configuration, please refer to the wiring diagram in the actaul system for installation.

TROUBLESHOOTING GUIDE.

Trouble, Alarm Codes Causes Corrective Actions

Pressure transducer alarm PRSA

Outlet sensor TS2 fails STSA

Room sensor TS3 fails ATSA

Coil/defrost sensor TS1 fails

CTSA

Aux sensor fails (if provided) T4SA

Low superheat LOSH

High room temperature HITA

Low room temperature

LOTA

Low pressure alarm

LPRA

Digital Input 1

XTA1

Digital Input 2

XTA2

Digital Input 3

XTA3

Door Alarm DROA

Communication COMA

• Bad transducer

• Out of range

• Loose wire

• Wrong hook-up

• Mechanical damage

• Connection wire loose

• Overheated

• Out of range

• Mechanical damage

• Connection wire loose

• Overheated

• Out of range

• Mechanical damage

• Loose connection wire

• Overheated

• Out of range

• Mechanical damage

• Loose connection wire

• Overheated

• Out of range

• Superheat setting too low

• Wrong locations of TS2

• Sensors may be loose

• Uneven feeding of coil circuits

• Overcharge of refrigerant

Defective electric expansion valve (EEV)

• Compressor stops

• Insufficient refrigeration

• Heat load too large

• Compressor fails or high pressure cuts out

• Evaporator fans may not run

• Door open for too long

• Coil iced-up

• Inproper low temp setpoint

• Over designed system

• Refrigerant leak

• Bad transducer

• Incorrect digital input MODE

• Mechanical damage

• Loose connection wire

• Out of range

• Incorrect digital input MODE

• Mechanical damage

• Loose connection wire

• Out of range

• Incorrect digital input MODE

• Mechanical damage

• Loose connection wire

• Out of range

• Door are open

• Incorrect parameter

• Bad door switch

• Loose RJ-45 coonection

• Failed communication port

• Replace the pressure transducer

• Turn off power for a few seconds, turn back on

• Toghten the connections

•

Wire correctly

• Replace the sensor

• Tighten the connection wires

• When brazing suction line, take out the sensor

• Install the sensor after brazing

• Tighten the connection wires on the controller

terminal

• The room sensor can be replaced by surface sensor

• Tighten the connection wires on the controller

terminal

• Let the sensor cool down to application temperature

range: –50oF to +103oF

• Replace failed sensor

• Tighten the connection wires on the controller

terminal

• Let the sensor cool down to application temperature

range: –50oF to +103oF

• Replace failed sensor

• Change to correct set point

• Make sure the distributor is feeding each circuit

evenly

• Insulate the sensors with foam tape

• Use correct refrigerant charge

• Check EEV wiring

• Replace defective EEV

• Check compressor

• Check system design to select a sufficient system

• Replace failed compressor

• Fix the evaporator fans

• Keep the cold room door closed during refrigeration

• Check possible air leak through the walls of cold

room

• Change low temp set point

• Re-select the system

• Fix leak

• Replace pressure transducer

• Correct the digital input MODE parameter

• Tighten the connection wires on the controller

terminal

• Replace failed sensor/switch/relay

• Correct the digital input MODE parameter

• Tighten the connection wires on the controller

terminal

• Replace failed sensor/switch/relay

• Correct the digital input MODE parameter

• Tighten the connection wires on the controller

terminal

• Replace failed sensor/switch/relay

• Close door tightly

• Declare the correct parameter relay (open/close)

• Change the door switch

• Replace connector

• Change a new controller board

Troubleshooting the Electric Expansion Valve

If the valve stops moving, depending upon how far open it is, one or more alarms may be displayed. These alarms include a low superheat alarm, a low temperature alarm, and/or a high temperature alarm.

Use the following steps to troubleshoot the valve:

1) Disconnect the valve from the controller.

2) The resistance between the black and white leads should be 90 ohms. The resistance between the black and red leads should be an open.

3) The resistance between the red and green leads should be 90 ohms. The resistance between the white and green leads should be an open.

4) The resistance between each lead and the brass housing of the valve should be an open.

5) Read the AC, not DC, voltage across the black and white leads while the valve is moving. The AC voltage should be 11 to 13 VAC. The voltage will be close to 0 VAC when the valve is not moving.

6) Repeat step 5 across the red and green leads.

If any voltage is out of tolerance, replace the controller. If the above steps pass, inspect for contamination in the valve or nicks on the seat of the valve.

CAUTION: If the valve was taken apart and was left running while taken apart, the piston may have come too far out of the motor assembly. If you reassemble the valve with the piston in this position, the threads in the piston will be stripped when the piston is forced into the seat while tightening the lock nut. Make sure the piston is drawn up far enough into the motor assembly before reassembling.

MASTER-BILT PART NUMBERS

Use the chart below when ordering replacement parts for your Master-Bilt Master Controller 2.0 refrigeration system.

Item Description Part Number Notes

Master Controller 2.0 Board Med. Temp. Cooler 19-14285 Please re-set for applications Master Controller 2.0 Board Low Temp. Freezer 19-14282 Please re-set for applications Electric Expansion Valve 19-13772 Connections: SER-6-1/2”x1/2” Electric Expansion Valve 19-13773 Connections: SER-6-5/8”x5/8” Low Pressure Transducer 19-14223 Suction Pressure 4-Way Reversing Valve 09-09776 7/8” Connections, 24VAC Coil 4-Way Reversing Valve 09-09783 1 3/8” Connections, 24VAC Coil Temperature Sensor 19-13967 30” Leads Temperature Sensor 19-13968 10 ft Leads 24VAC Control RELAY 19-13986 For compressor control 24VAC, 40VA Transformer 39-01088 120/208/240 V Primary Wireless Router 19-14294 Fast MB Master-Controller, Commercial Range, 5 Port 10/100 Fast Ethernet Switch, 8 Port 10/100 19-14288 Cable: 50 feet Ethernet Cat5e, 19-14290 With Ethernet Switch Cable: 25 feet Ethernet Cat5e 19-14289 Use between AMCs Cable: 100 feet Ethernet Cat5e 19-14291 With Ethernet Switch Valve Test Kit 19-13786 Recommended for service Fuse, BK/MDL-1/4, Time Delay, for AMC 19-14299 for AMC, Vendor: KE2Therm

For condensing unit installation and wiring, please consult the Master-Bilt Condensing Unit System Installation and Operation Manual. If any discrepancy is found in this manual, please contact Master-Bilt Technical Service Department immediately.

19-14287

908 Highway 15 North

New Albany, MS 38652

Service Dept. phone: 800-684-8988

Fax: 866-882-7629

Email: service@master-bilt.com

Rev. 8-26-2013

Master-Bilt Master Controller 2.0 Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual