Carel mRack - 1 Product; General Functions; Main Characteristics

µRack
Cod. CAREL +03P220431 rel. 0.0 del 08/09/05 - preliminary version
3
1. Product
1.1. General functions
1. Read pressure transducers, display data in BAR/°C (depending on the type of refrigerant gas)
2. Management of compressors with the same and different capacities
3. Management of compressor racks with two circuits, MT and LT
4. Setting of the number of compressors – fans on the unit
5. Rotation of the compressors (FIFO and by time). FIFO rotation of the fans.
6. Fan speed control (PWM OUTPUT)
7. Compressor and fan dead band management
8. Possibility to enter the compressor set point in BAR and display the value in °C by pressing the “UP” and “DOWN” buttons together when displaying the
parameter values.
9. Possibility to enter the fan set point in BAR or degrees centigrade, depending on the control probe used (pressure or NTC).
10. Multifunction input: general HP alarm, ON/OFF, change SET POINT,…
11. Set point variation from digital input
12. Possibility to set the compressor-fan thermal overload/generic alarm as automatic/manual
13. Enable compressors from the “Maintenance” screen
14. Proportional plus integral function for the fan inverter.
15. Floating condenser set point
16. Optional temperature probes, with high temperature alarm threshold:
a- Outside air
b- Ambient air
c- Compressor discharge temperature
d- Suction temperature
1.2 Main characteristics
Main functions
• Control of compressor suction pressure
• Control of condensing pressure (compressor discharge)
• Complete management of the outputs available;
• Complete alarm management;
• Connection to serial line for supervision / telemaintenance;
Devices controlled
• Compressors (up to 4 hermetic compressors, no part load)
• Condenser fans (max 4)
• PWM speed control
Programming
• Display and control of the values measured, on LED display
• Three levels of parameter protection: SEL (USER), PRG (INSTALLER), SEL+PRG (MANUFACTURER)
• Possibility to configure all the unit parameters using a hardware key.
• Possibility to configure the main unit parameters via serial line.
• Possibility to modify the access level to the parameters from the keypad (only from MANUFACTURER level).
Hardware
• The product comes ready for panel installation, 32x74, and DIN rail mounting.