INTRODUCTIONINTRODUCTION

MAIN COMPONENTSMAIN COMPONENTS

FUNCTIONSFUNCTIONS

Conventionally, the cabs of electric locomotives are equipped with 2 nos. cab fans and 2 nos. heaters for the crew in each cab. In extreme summer and winter conditions the existing system is inadequate for reasonable level of comfort to the crew. To improve this uncomfortable condition, Railways has introduced AC unit in the driving cabs of electric locomotives.

These AC units are being purchased as per RDSO spec. no. RDSO/2007/EL/SPEC/0055 (Rev’0’), November 2007. This assembly is of roof mounted package unit type and each locomotive is being provided with 2 independent AC units with interlock so that only one unit will work at a time

The compact unit have following functions -a) Cooling capacity – 2 t at 35ºC ambient.

1.5 t at 50ºC ambient.

However, the AC unit is able to operate upto 60ºC ambient without tripping, damage and any other faults.

b) Heating capacity: The unit have overall heating capacity of 2 KW.

c) The temperature inside the cab shall generally be maintained between 25-30ºC.

Air filter14.Blower 7.

Step-Down Transformer

13.Blower motor 6.

Control Panel12.Evaporator coil 5.

Filter Drier11.Condenser Fan motor 4.

VANE Relay10.Condenser fan 3.

HP and LP Cutout9.Condenser coil 2.

Thermostat8.Compressor 1.

COMPRESSOR

HP & LP CUTOUT

CONDENSER FAN MOTOR

CO

ND

ENSE

R

CO

ILCONDENSER CONDENSER FANFAN

THERMOSTAT

HEATERHEATER

EV

AP

OR

ATO

R

EV

AP

OR

ATO

R

CO

ILC

OIL

BLOWER MOTOR

BLOWER

BLOWER

VANE relay

Air Filter

11

Filter drier

22

� Only blower will run to circulate the air.� Compressor and condenser motor and heater will be in OFF position.

TERMINAL BLOCK CONTACTOR

BLOWER

CONTACTOR HEATER

MCB HEATER MCB

COMP.COMP. OVERLOAD

RELAY

CONTACTOR COMP. & COND. MOTOR

OPERATION OPERATION

1. Keep the Rotary switch on Vent.

2. Switch ON BL1RA, main supply indicator (Red) will glow.

3. Blower will run and blower indicator (Green) glow, if blower motor is not working Air loss indicator (Red) will glow.

4. Select mode Cool/ Heat.

5. In cool mode pressure switch will monitor the rotation of the compressor for 30-60

6. Seconds if rotation is not correct the indicator (Red) for Phaseloss/ reversal will not glow and cooling will not take place andcool indicator (Green) will also not glow.

7. In cool mode if condenser fan motor is not working HP indicator (Red) will glow in 1-2 minutes (if ambient temp. is low, trip time may increased).

8. Similarly, in Heat mode heat indicator (Green) will glow, in case of over heating, OHP indicator (Red) will glow.

Control Panel WORKING MODESWORKING MODES

.

.

There are three modes of operation to select in which the unit will run:Vent Mode

Cool Mode

Heat Mode

.

� Blower in ON position.� Heater will be in ON position.� Temperature in the room is maintained by the thermostat by switching

the heater ON/OFF automatically with respect to set temperature.

� Blower in ON position.� Compressor and condenser motor will ON with a time delay from

start. For this a Time delaying relay is provided in the control circuit of the compressor

� Temperature in the room is maintained through thermostat by cut-in and cut-off of the compressor, accordingly to the set temperature

INTERLOCKSINTERLOCKS

� If blower motor is not ON, other equipment cannot get switched ON.� If condenser fan is ON, the compressor can get switched ON.� If heater is ON, compressor will not switched ON.� If single phase/ reverse sequence of phases occur, compressor will be

switched OFF.

The following interlocks have been provided in the control panel:

33 44

LED INDICATIONSLED INDICATIONS

� MAINS ON – This will glow when power supply to the unit is live.

� BLOWER ON – Glows when the blower is running.

� COMPR/COOL ON – Glows when the compressor is in ON position.

� HEATER ON- Glows when the heater is in ON position.

� AIR LOSS - Vane relay not energizing, blower failure/

� HP – Glows when the pressure of compressor is high.

� LP – Glows when the pressure of compressor is low.

� OHP – Glows when there is excess of heat through heater.

� COMPR. OLR – Glows when over load relay of compressor trips due to high load current.

� Ph. LOSS/ REV/ UNHEALTHY – Glows when the compressor not working in proper direction or facing single phasing.

MAINTENANCE SCHEDULE MAINTENANCE SCHEDULE Following maintenance schedule is proposed by CAMTECH for AC

unit provided in electric locomotive cabs and is based on RDSO’s SMI No. RDSO/PE/SMI/AC/0044-2011(Rev.0) dated 02/04.11.2011 for RMPU of LHB Coaches. Necessary additions, corrections may be done as per OEMs recommendations and failure trends observed by Railways.

55 66

Schedule Activities

�����Check the working of all LED indications for proper functioning.

d.

�����Check working of rotary switch by rotating forward and backward.

c.

�����Check that the micro-controller is firmly mounted.

b.

�����Check intactness of microcontroller connections.

a.

Micro controller2.

To be replaced

����Check that earthing shunt of RMACU is intact with loco roof.

f.

���---Ensure that there is no damage/ crack in structure frame of RMACU.

e.

�����Attend or replace defective/ by passed components.

d.

���Clean air filters by removing the filters, rinsing through in the reverse direction to the airflow. High-pressure water should not be used, as this will damage the filter media. Take care to blow in the opposite direction to flow air in the System. If there are cut marks / torn off filter media, replace the filter.

c.

�����Run the plant in all modes, observe for any abnormality and got attended.

b.

�����Check the loco logbook and attend the defects recorded by driver during run.

a.

1.General

IOHAOHICIBIAActivities

To

be r

epla

ced

To

be r

epla

ced

1. Check the loco logbook and attend the defects recorded by driverduring run.

2. Clean air filters every trip/week by removing the filters, rinsing through in the reverse direction to the airflow. High-pressure water should not be used, as this will damage the filter media. Take care to blow in the opposite direction to flow air in the System. If there are cut marks / torn off filter media, replace the filter.

3. Check the working of AC unit in all three modes for proper functioning.

Trip Schedule

���----Ensure proper clamping/harness of electrical wires to heater.

b.

���----Ensure proper mounting of heaters without touching side bodies.

a.

Heaters5.

��

------Check electrical terminal box is

properly tightened & cables are terminated with lugs.

e.

��------Check leakage from suction & discharge port.

d.

IOHAOHICIBIAActivities

To be replaced

�

�----Ensure earthing shunt is intact.c.

Compressor4.

���----Check and ensure holding clamps from top are properly tightened.

a.

���----Check and ensure mounting fasteners are properly tightened.

b.

���----Lubricate condenser fan motor and blower motor if there is provision.

f.

���----Ensure that blower impellers are properly tightened.

e.

To be replaced

��----Ensure earthing shunts of motors are intact.

d.

��------Check electrical terminal boxes of motors are properly tightened & cables are terminated with lugs.

c.

���----Check and ensure mounting fasteners are properly tightened.

b.

���----Check visually condenser fan blade and ensure that there is no crack on the blade or hub.

a.

Condenser fan motor/ blades and Blower motor/ Impeller3.

��------Ensure that capillaries of distributors to evaporator coil are not having any sharp bend or kinks.

c.

Evaporator Coil 8.

���----Ensure that there is no damage to fins.

a.

���----Check that the mounting fasteners are properly tightened.

b.

IOHAOHICIBIAActivities

��------Check leakage from joints of HP/ LP cutouts and filter drier with soap solution.

b.

���----Ensure that control wires to HP/ LP/ OHP cutout and pressure switch are properly clamped/ harnessed.

c.

Refrigerant Pipe Line/ Capillary7.

���----Check visually for proper clamping/ support.

a.

���----Ensure proper clamping/ supports are connected to HP/ LP/ OHP cutout and pressure switch.

b.

���----Check that the mounting fasteners are properly tightened.

a.

OHP, HP, LP Cutout and pressure switch 6.

���----Ensure temperature probe, thermostat and its control wires are properly mounted and intact.

e.

��------Check and clean thermostat temperature probe.

d.

���----Check dust accumulation on heating element. Remove gently, if required.

c.

77 88

���----Make sure condensate / rain water drains properly. This can be checked by opening the evaporator top and condenser top of the system arid by pouring water in to the drip tray and clean the drip tray pipe by adequate size of round brush. It should be assured that there is no clogging in drain pipes.

b.

��------Ensure that air passes only through evaporator coils and no air is bypassed directly to blower chamber.

c.

IOHAOHICIBIAActivity

���----Ensure that there is no leakage of condensate water from drip tray to electrical box & blower housing area.

a.

Drip Tray10

���----Clean the condenser coil by compressed air. Take care not to bend or damage the fins.

d.

��------Ensure that air passes only through condenser coils and no air is leaking through passages.

c.

���----Check that the mounting fasteners are properly tightened.

b.

���----Ensure that there is no damage to fins.

a.

Condenser Coil 9.

�--------Clean evaporator coil by Steam/ compressed air by opening the evaporator panel cover from roof top of the loco. Take care not to damage any fins.

d.

��------Check the tripping of heaters i.e. The testing of OHP setting shall be done by switching off the blower. During testing, the probe of digital thermometer shall be placed near the sensor of OHP & the display shall be kept outside.

g.

��------Check all safety controls by forcing them to trip by disconnecting the wire of the blower motor to cause compressor tripping on low pressure and by disconnecting the wire of the condenser fan motor to cause compressor tripping in high pressure.

f.

��------Check heater at the beginning of winter season and replace if defective, this can be done at control panel by checking current drawn with Tong Tester.

e.

���----Check & Clean control transformer and its connections.

d.

��------Check and replace thermal insulation if required.

c.

��------Check and clean contacts of contactors and replace pitted contacts if required. Tighten all terminals in control panel.

b.

IOHAOHICIBIAActivity

�����Check and clean all terminals in the control panel.

a.

Electrical 11

99 1010

(For Official Use Only)

PAMPHLET on

ROOF MOUNTED AC UNIT of ELECTRIC LOCOMOTIVE CAB

Hkkjr ljdkj GOVERNMENT OF INDIA

jsyjsyjsyjsy ea=ea=ea=ea=kykykyky;;;; MINISTRY OF RAILWAYS

CAMTECH/E/13CAMTECH/E/13CAMTECH/E/13CAMTECH/E/13----14/LOCO14/LOCO14/LOCO14/LOCO----CabCabCabCab---- AC/1.0AC/1.0AC/1.0AC/1.0

August, 2013August, 2013August, 2013August, 2013

egkjktiqj, Xokfy;jXokfy;jXokfy;jXokfy;j & & & & 474 005474 005474 005474 005Maharajpur, GWALIOR - 474 005

It is clarified that this pamphlet does not supersede any existing provisions laid down by RDSO, Railway Board or Zonal Railways. The pamphlet is for guidance only and it is not a statutory document.

If you have any suggestion or comment, please write to:Director (Electrical), CAMTECH, Maharajpur, Gwalior (M.P.) – 474 005

Ph.0751-2470740, Fax 0751-2470841E-mail: direlcamtech@gmail.com

Disclaimer

� Don’t change the set temperature of thermostat frequently.

� Don’t cover the air path.

� Don’t change the sequence of 3 phase supply.

� Don’t open cab windows frequently.

� Do not break/ open the sealed air conditioning system.

DODO’’ss

DONDON’’TsTs

� Switch OFF the main supply before carrying out the maintenance.

� Clean air filters regularly by 1 bar air pressure on reverse side.

� Ensure that all the gaskets of corridor-door glasses are intact.

� Ensure that all the gaskets of corridor-door and cab door are intact.

� Ensure that all the glasses of cab are intact and there shall be no crack in glasses.

� Ensure that all the doors and shutters are moving and locking properly

WARNINGWARNING

Phogene gas (deadly poison) is generated when refrigerant is exposed to flame.

CAUTIONCAUTION

Ensure adequate ventilation during repairs.