Master Controller 2.0v24 Reverse Cycle Defrost System Installation & Operations Manual An Electronic Microprocessor-Based Electric/Mechanical Expansion Valve Refrigeration Control System With TCP/IP Internet Monitoring Feature May 2015 PN 888-88889 ©2015 Master-Bilt Products, an unincorporated division of Standex International Corporation. All rights reserved. Printed in U.S.A.
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.
TABLE OF CONTENTS INTRODUCTION .................................................................................................................. 4 WARNING LABELS AND SAFETY INSTRUCTIONS .......................................................... 5 APPLICATIONS .................................................................................................................... 5 MASTER CONTROLLER LAYOUT ...................................................................................... 6 Description ......
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.
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.
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”.
Evaporator Evap Coil In/ Defrost Temp. Sensor Liquid Line Pressure Transducer Suction Line Distributor Evap out / Fan Delay Temp Sensor Room Temp Sensor Electric Expansion Valve T1 T2 T3 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. .
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.
Sequences of Operation START UP When power is applied to the board, the controller closes the valve. The controller will display ‘STUP’ on its four-digit 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.
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 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.
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.
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.
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).
Definition of On-Board Symbols STATUS, DEFAULT AND READING DISPLAY When the on-board green light is on, the compressor relay is energized. When the green light is blinking, the room temperature sensor is satisfied, but waiting for the minimum off time or minimum run time 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.
TYPICAL SET POINTS FOR AMC CONTROLLER 2.0 SETPOINT “STPT” Air/Electric Defrost masterbiltstandex@gmail.
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.
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.
Temperature Sensors o o The application range of the temperature sensors used for this controller is -60 F to +150 F. 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.
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 32 0 5.123 -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.
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 MasterBilt 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 recommended charging procedures are: (1) Charge the system by weighing exact amount of refrigerant specified by Master-Bilt for the unit. Or, (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.
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 Controllerequipped 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.
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 a
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.
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.
908 Highway 15 North New Albany, MS 38652 Service Dept. phone: 800-684-8988 Fax: 866-882-7629 Email: service@master-bilt.com Rev. 4-7-2015 ©2015 Master-Bilt Products, an unincorporated division of Standex International Corporation. All rights reserved. Printed in U.S.A.
