Controller for Roof Mounted AC Package Unit (RMPU)
This Controller for Roof Mounted AC Package Unit of LHB Coaches and Double Decker Coaches is a Microcontroller based unit developed to control the sub-systems of the RMPU automatically according to the Heating, Ventilation and Air-Conditioning (HVAC) algorithm to provide accurate control thus resulting in comfort to passengers
RDSO Specification: RDSO/PE/SPEC/AC/0139-2009 REV.1
Approved by RDSO (Research Designs & Standards organization), Ministry of Railways,Govt. of India.
PIS for Stations
GPS based PIS for EMUs/MEMUs/DEMUs
Controller for Roof Mounted AC Package Unit
Emergency Lights for coaches
GPS Clocks for Platforms
Power Converter for Coaches & Locos
Battery Charger for Coaches & Locos
Intelligent Power Management Unit (IPMU)
Auto BTS site Manager
Aviation Warning Lamp
DC Energy Meter
The Microprocessor Controller consists of one Control Unit and one Display Unit. Control Unit monitors and controls the sub systems of two RMPUs by sensing different temperatures like Return-Air temperature, Fresh-Air temperature, Supply-Air temperature and Humidity of the Return-Air etc. by means of various sensors fitted in RMPUs.
It also continuously monitors the health of RMPUs and the log of events is stored in “Event Recording System” , while the list of faults are stored in “Fault Storage System”. The Events & Faults stored in memory can be downloaded through USB port by inserting the USB drive. The health status of the subsystems are also displayed by the glowing LEDs provided on the Control Unit.
Display Unit, as a part of the Microprocessor Controller, consists of a graphical LCD and few navigation keys. It is used to display Date, Time, Coach Number, RMPU Number and Make, Status of the RMPU’s sub-systems, various temperature set points etc. It enables to change the defaults settings of the above mentioned parameters through navigation keys. The messages displayed on the Display Unit are under the control of Control Unit.
The communication between the Control Unit and Display Unit is through an RS-232 port. RS-485 Communication Port is also provided for GSM/GPRS connectivity for centralized control, as a future requirement.
Type of Switching
Type of switching
Number of Analog Input Sensors
Analog Inputs (Current loop)
Type of switching
Communication between Control and Display Units
Size (LxDxH) in mm
Control Unit / Display Unit
110 V +/- 30% DC / AC
1A (max.) at 100VDC.
Relay contacts (normally open contacts).
4 – 20mA.
Control Unit 330 x 70 x 260
Display Unit 230 x 27 x 118
CRCA Sheet with RAL 7035 Powder Coating
-20° to +70°C
Note : Product improvement is a continuous process and the specifications can change anytime without any notice.