Unit installation

50
MICROPROCESSOR CONTROL SYSTEM
INTRODUCTION
This section is to describe the chiller control system. The hardware will have the following characteristics:
• Components UL approved.
• The components legends, polarity and pin #1 of IC are identifiable on silk screen on PCB.
• QC check will be marked on each tested PCB.
• For EMI interference the controller is compliant to EN 61000-4-4 class 4 for I/O and power supply, EN 55011
for conducted emission on power supply cable limit class B, EN 61000-3-2 with limit class A for harmonic
current distortion, EN 61000-3-3 for supply fluctuation and flickers.
• Built using SMD (Surface Mount Device) technology.
• 16-bit Mitsubishi microprocessor with a 128Kb (or 256Kb TBD) “flashes” EPROM memory.
• Flash memory can be programmed “on board”, through PC or Hardware Key; i.e. there’s no need to replace
the component it to upgrade the software.
• Real Time Clock on board
The system architecture is as follows:
• User interface “CO1” with LCD display.
• One master controller board with an user interface “CO1” for the first 2 compressors connected via serial bus
(RS485);
• One compressor board (slave) for each additional circuit/compressor pair, serially (RS485 same as master –
user connection) connected to the others;
The board’s technical specs are the following:
Master board and slave compressors board:
• Dimensions mm. 291 x 137 mm
• Power supply: 24 Vac ±10% 50/60Hz, 20 VA protected by 5x20mm fuse 1.6AT.
• Temperature range 0÷70°C.
• 10 bit A/D converter on-board.
• 18 DIG-OUT relays.
• 4 ANALOG-OUT.
• 20 DIG-IN alarms 115 VAC.
• 12 ANALOG-IN
• Serial interface for User board / Slave board connection (485)
• Serial interface option for Remote Monitoring System / micro programming (With 485 / 232 adapter)
• Serial interface for EEV board connection (485)
• Serial interface for Power line analyser (485)
• Serial interface for Hardware Key (SPI)
User Interface board description:
• Dimensions mm. 220 x 111mm
• Temperature range 0÷70°C (extended temperature range LCD).
• 3 digits LED 7 segments display for temperature.
• 20x4 characters LCD back illuminated display for status and alarms.
• On-board 6 buttons keyboard:
1. SET to enter in set mode and change the set point
2. UP to scroll up or increase values
3. DOWN to scroll down or decrease values
4. ESC alarm reset or menu quit key
5. ON/OFF
6. MENU available for future implementations
• 3 on-board LEDs:
LOO On Off
1. LM setup menu active
2. LA Alarm condition