Cat Electric Rope Shovel MPV9VX1C M9-575V Operation & Maintenance Manual - PDF DOWNLOAD

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SIGMA Manual Number Date of Original Issue Date of This Issue

: : :

MANUAL MODEL TYPE APPLICATION

: : : :

JOB NUMBER

:

MPV9VX1C December 2002 December 2002

M9-575V MPV9VX1C Package Mining Drills, Shovels, Draglines 9071

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CHAPTER 1

UNIT DESCRIPTION AND SPECIFICATIONS

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1.0.0 DESCRIPTION OF UNIT The MPV9 is a heavy-duty system suitable for rooftop or walkway mounting on the cabs and electrical enclosures of mining and industrial equipment. This includes shovels, draglines, drills, ship loaders, track maintenance, crane cabs and control rooms.

Evaporator:

Air is drawn from return air spiggot’s, passes over the heat exchange coil and heating elements into the double inlet wheel fan deck and is discharged through the supply air spiggot’s into the conditioned space.

Refrigerant flow is metered by an externally equalized TX valve, and is cut off by a liquid line solenoid valve.

Heat exchange coil is large, with heavy gauge tubing and coarse fin pitch to reduce clogging.

Fan motor is single shaft and has totally enclosed, fan-cooled construction.

Drain pan is large and of "V" design for ease of cleaning and to facilitate draining.

All pressure controls are in the evaporator section and are fully sealed, preset and ‘O’ ring connected.

Condenser:

The compressor is a heavy duty, fully sealed scroll device. The assembly is mounted to heavy flexible mounts to reduce noise transmission to the structure and provide some damping of shock.

Connections are either soldered, ‘O’ ring or rotalock.

A large filter drier is mounted in the liquid line to filter and remove moisture from the refrigerant. Isolation valves are installed on either side to enable refrigerant to be "pumped down" and thus enabling core to be replaced without total loss of refrigerant.

Condenser fan is single speed.

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1.0.0 DESCRIPTION OF UNIT (cont.)

Electrics:

The main control panel is mounted on top of the evaporator lid for ease of service. Switchgear is Klockner Moeller, and motor protection is by circuit breaker thermal overloads. Heaters and transformer have circuit breakers. Starter switchgear is provided to remote control high voltage pressurizer supplied by others.

The pilot controls, when supplied, have OFF-LOW-HIGH fan switch and HEAT-VENT-COOL-DEMIST mode switch, plus a set point adjuster for thermostat.

A transformer supplies the 115V for control purposes.

Pressurizer: Provided by others.

1.1.0 Specifications Dimensions

:

T9071500

Electrical Schematic

:

AE9071024

Nominal Cooling Capacity :

31,000 Btu/hr. @ 575V/60Hz

Heating Capacity :

12 kw @ 575V/60Hz

Power Requirement:

575V/3ph/60Hz

Refrigerant

:

HFC 134a environmentally friendly 24 lbs.

Oil

:

POE Variety Mobil Artic EAL22CC or ICI Emcarate RL32CF

Compressor

:

Fully sealed scroll compressor.

Condenser Coil

:

5 row, 3/8” inch copper tube with 8 aluminum fins per inch.

Evaporator Coil

:

4 row, 3/8” inch copper tube with 10 aluminum fins per inch.

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1.0.0 DESCRIPTION OF UNIT (cont.)

1.1.0 Specifications (cont.)

Condenser Fan

:

Multi-blade axial, 17¼” inch diameter, 35o pitch to provide in excess of 3000 cfm @ 60Hz.

Supply Air

:

One forward curve double inlet fan supplies a nominal 1300 cfm (610 l/s) @60Hz,

Pressure Controls :

HIGH-228/325 psi high pressure cut out, manual reset.

LOW - 10 psi cut out 25 psi cut in

Thermostat

5 stage electronic 1.5°C within stage.

:

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CHAPTER 2

COMMISSIONING

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2.0.0 INSTALLATION AND COMMISSIONING Time spent ensuring the preparation for installation will pay dividends by reducing service requirements during operation.

2.1.0 Commissioning The system has been fully charged and commissioned at the factory, but must be site checked.

With all cabling run, and system mounted, the system is ready for commissioning.

• •

•

Turn selector switch ‘OFF’.

Select and wire the primary side of the transformer to ensure 110-120V single phase control. This is VERY IMPORTANT as the transformer is multi-tapped and correct control voltage will aid reliability.

Check control voltage is 115V.

Proceed to live test.

A.

Select ‘VENT’ on Mode switch.

Select ‘LOW’ on FAN switch.

This should result in evaporator fan running on low speed and pressurization unit only.

Check correct phase rotation of evaporator fan. This can be done by either switching ‘OFF’ and have an observer looking into the evaporator cover; or by closing the Main Isolator at the unit if on you own.

Please be aware that air will flow in the right circuit no matter what direction the fan runs - but the wrong direction will only result in approximately 30% of the flow.

Select ‘HIGH’ on Fan switch and check that speed and flow increase.

B.

Select ‘HEAT’ on Mode switch.

Rotate thermostat knob fully clockwise.

Under normal temperatures of 70°F nominal, both heater

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2.1.0 Commissioning (cont.) contactors will close bringing on both heat stages.

In the event that ambients and the cab temperature are too high, immerse the temperature probe (in return air section of evaporator) in a glass of cold water.

Check the individual staging of heater contactors as the probe either cools - or warms up.

Check HIGH & LOW fan operation. Fans will automatically switch to HIGH in high heat.

C.

Select ‘COOL’ on Mode switch.

Rotate thermostat adjustment fully counterclockwise.

As with heating, the ambient should be in the 70°F range for cooling to operate.

In the event that it isn’t, warm the return air probe in you hand. The compressor should start, along with the condenser fan.

If the compressor does not start, check phase rotation as a device is installed to ensure correct rotation.

Observe the charge as indicated in the liquid line sight glass (located in the condenser). The air conditioner is fitted with a HEAD PRESSURE CONTROL VALVE which maintains a minimum pressure of 130 psi at all ambients. This works by backing refrigerant up into the condenser. Charge in the air conditioner is high for this reason, but it provides great flexibility of application.

System should be capable of operating in the COOLING mode down to 10°F ambient.

Check fan speed operation.

D.

Select DEMIST on Mode switch.

This mode assists in demisting inside the cab window surfaces by operating one stage of heating continuously and either COOLING if it is hot, or 2nd stage of HEAT if it is cold.

Heating the air dries it and by passing over a cool heat exchange

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2.1.0 Commissioning (cont.)

coil, moisture is condensed and removed from the air stream. This greatly increases the speed of demisting.

Check fan speed operation, but again be aware that full heat will result in HIGH fan.

OPERATION MATRIX Evap. Fan Pressurizer Heat st Low High 1 2nd OFF LOW HIGH HEAT VENT COOL DEMIST

X

X

X X X X X X

X = Operational T = Thermostatically Controlled

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T X

Cooling

T T

T T

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CHAPTER 3

SERVICING

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3.0.0 SERVICING Recommended service schedule. Site conditions may alter this.

1st Week

Daily

Monthly

3 Months

Annually

Check charge and add if required.

Leak Test - with ultraviolet black lamp and 134a specific detector, good for use with Ester lubricant system. Spectronics Corp GS-2/E Glow-Stick Capsule recommended..

Tighten all mounting bolts, fasteners, terminals, etc.

Check drains.

Check operation.

Clean filter if in dusty conditions.

Clean pressurizer if in dusty conditions.

Observe charge.

Daily checks.

Check for leaks.

Check fans for tightness on shafts.

Clean out coils.

Flush drains.

All monthly phases.

Check structure.

Check hoses and fittings.

All previous phases.

Give system a good cleaning out.

Check motor bearings and replace if necessary.

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CHAPTER 4

FAULT FINDING

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4.0.0 FAULT FINDING This section is written on the assumption that the service mechanic is a qualified trades person in refrigeration and air conditioning. They must have a good understanding of the operation prior to fault diagnosis and repair.

4.1.0 System Dead • • •

Check main supply and circuit breakers.

Check control transformer.

Check power lines on AE9071024 to ascertain where power is lost.

4.2.0 No Fans • •

Check power lines to find where the loss or break in supply occurs.

Check motors.

4.3.0 No Cooling All fans OK, but compressor doesn’t run.

• • • • • • • • • • •

Check “COOL” selected, and if there is 115V power to terminal 22.

Check HP and LP control are closed by testing for 115V at 11 (reset HP anyway - in evaporator liquid line). If LP is open, system may have lost charge. Find leak and repair.

Check that pumpdown relay closes and 115V power is supplied to compressor thermal overload.

Check that liquid line solenoid valve operates.

If power is supplied to the contactor, but no action, the coil will have failed.

Check contactor is closing.

Check overloads, circuit breakers.

Check phase rotation relay.

If power is being supplied to the compressor, but still no action, isolate the power, disconnect the terminals and check for open circuit in the motor.

If breaker keeps tripping, the compressor may be grounded.

Check thermostat operation and stage 3 is closed between K3C and K3NO.

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4.0.0 FAULT FINDING (cont.)

4.4.0 Inadequate Cooling System may not be performing as well as it should be.

•

Check pressures. A system would normally operate between 130200 psi on the high side and 25-45 psi on the low side.

High pressure could indicate air in the system, dirty condenser, overcharge. Low high side pressure could indicate low charge or failing scroll in compressor.

If the low side has a much higher than 45 psi pressure it could indicate failing compressor, liquid floodback, and/or poor TX valve, operation (is suction line very ‘sweaty’?).

•

Check refrigerant charge in sight glass. It should be full at all times when compressor is running. Low charge will first become evident at low ambients.

•

Check for restriction in the system. This can be done by feeling the plumbing before and after a “device”. If it is noticeably cooler, expansion has taken place from a drop in pressure. There is restriction, and steps should be taken to clear it. Check for a:

Blocked return air filter.

An open lid admitting outside air.

Coil for cleanliness.

TX valve for correct operation.

4.5.0 Charge Normal factory charge is 24 lbs. of 134a to cater for low ambient operation as the condenser fills with refrigerant. If bubbles appear in the sight glass, check for leaks, repair and either weigh in the full charge if system has been evacuated or top up as conditions demand. The system is forgiving for normal site practices.

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4.0.0 FAULT FINDING (cont.)

4.6.0 Heating The system has 6 equal elements in star formation and as the system operates in extremes of ambients, a high capacity system has been provided. It is also 2 stage in operation for improved comfort.

If heating is inadequate, check: • • • •

Circuit breakers. One breaker will knock out 1/3 of that stage capacity.

Elements for open circuit.

Thermostat for correct switching of contactors.

Over temperature sensor cutting out failed evaporator fan.

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SERVICE NOTES: 4.7.0

HEAD PRESSURE CONTROL VALVE OPERATION

The Head Pressure Control Valve’s purpose is to hold back enough of the condensed liquid refrigerant so that some of the condenser surface is rendered inactive. This reduction of active condensing surface results in a rise in condensing pressure and sufficient liquid line pressure for normal system operation. Due to the presence of the Head Pressure Control Valve the refrigerant charging procedure is as follows.

CHARGING PROCEDURE MPV9 The following procedure requires the unit to be void of all refrigerants and in a vacuum.

The MPV9’s total system refrigerant charge is 24lbs 1.

With the unit off, dump charge 4lbs of 134a at the receiver outlet valve (the filter dryer evacuation port can also be used.)

2.

Connect the low side gauge to the charging port provided at the TXV (Just above the distributors.)

CAUTION: DO NOT CHARGE FROM THE SUCTION PORT!

3.

With the unit off, charge as much of the remaining refrigerant as the system will allow (this number will vary depending on ambient temperature.)

4.

Switch the unit into cooling.

5.

Continue adding refrigerant until the full 24lbs have been added (depending on the ambient temperature, the low pressure switch may need to be shorted to allow the system to continue to run until a sufficient charge has been added.)

WARNING: The compressor is phase rotation sensitive, and will not function if wired incorrectly. Equal pressure at the discharge valve and the Suction valve is one symptom of the compressor running in the wrong direction. Do not allow the system to run in this condition for any extended period of time. Damage may occur! In the event of a compressor change, the phases must be checked at the compressor. Correct rotation can be felt with discharge to condenser getting hot, and suction back is cool.

T1 - 102 Compressor Wiring

T2 - 202 T3 – 302

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CHAPTER 7

RECOVERY OF REFRIGERANT

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7.0.0 RECOVERY OF REFRIGERANT Although HFC134a is environmentally friendly, the refrigerant must be recovered prior to opening up the system. Devices are fitted to minimize the amount required, but venting to atmosphere is illegal.

The lubricant is a POE style, and does not mix with other mineral oils.

A dedicated recovery unit should be used, as should a gauge set.

THEY SHOULD NOT BE MIXED WITH R12, R22, MP39, OR OTHER REFRIGERANTS.

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CHAPTER 8

134a SPECIFIC TOOLS

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8.0.0 134a SPECIFIC TOOLS 665-C027 532-C005

UV Lamp Manifold Gauge Set with Isolation Valves at Hose Ends.

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