Service Replacement Of The 9Y-1784 Pyrometer Or The 7E-0870 Digital Pyrometer With The 133-6333 Pyrometer Or The 133-6334 Pyrometer {0776} Caterpillar

Engines:

3606 (S/N: 8RB1-UP)

3608 (S/N: 6MC1-UP)

3612 (S/N: 9RC1-UP)

3616 (S/N: 1PD1-UP)

Introduction

This Special Instruction provides the necessary installation, setup, and operating instructions that are required for the 133-6333 Pyrometer (°C) and the 133-6334 Pyrometer (°F).

The pyrometer is capable of monitoring nine separate temperatures by using the Type K thermocouples. Typically, eight engine exhaust temperatures and the turbocharger inlet can be monitored. If more than eight cylinder exhaust temperatures are going to be monitored, two digital pyrometers are used.

For added protection, the data to the thermocouple at channel "0" is continuously compared against a high limit set point selected by the operator. When the setpoint is exceeded, a switch is closed to the power supply negative. This information is processed in the annunciator panel or another monitoring system.

The entire Special Instruction should be read and understood before beginning work.

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Personal injury can result from improper engine operation. Deviation from these installation instructions can result in improper engine operation which could cause personal injury. Follow the installation instructions before engine operation.

Reference: Consult the Parts Manual, the Service Manual, and the Electrical Schematic that are provided with the engine.

Required Materials

Illustration 1	g00310826
133-6333 Pyrometer (°C)

Illustration 2	g00310827
133-6334 Pyrometer (°F)

• 133-6333 Pyrometer (°C)

• 133-6334 Pyrometer (°F)

• Mounting Frame

• Type K Thermocouple's Extension Wire

• Type K Ungrounded Thermocouples

• Conduit

• Relay

Installation

Mounting

The pyrometer(s) can be mounted in the control panel. The pyrometers can also be mounted on a different suitable flat surface with the display at a convenient height for viewing. The pyrometer fits a mounting face for a round gauge with a 114.3 mm (4.50 inch) diameter.

If the enclosure has a door, the faces of the pyrometer(s) should be inserted far enough so that the door will not hit the push buttons.

Note: Avoid mounting the Liquid Crystal Display (LCD) in direct sunlight. The display's temperature range is -40°C to 79°C (-40°F to 175°F). The setpoint switch will operate over a range of -40°C to 85°C (-40°F to 185°F).

Specifications

Required Power ... 12 V to 125 V DC, 0.4 WATT

Display ... 10.2 mm, Five Digit Liquid Crystal Display

Accuracy ... ± 1% of Reading, ± 3 Degrees

Update Rate ... 3 Times Per Second

Ambient Temperature Range ... -40°C to 80°C (-40°F to 175°F)

Temperature Range ... 0°C to 815°C (32°F to 1500°F)

Rating Of The Output Switch ... 120 V DC, 0.2 A continuous

Automatic Cold Junction Compensation

Signal From The Type K Ungrounded Thermocouple

Wiring

Power

Illustration 3	g00310829

The pyrometer is designed to be powered by a 12 volt to 125 volt DC power source. Connect the power source to the pyrometer. Observe the back of the pyrometer in order to ensure that the polarity is correct. Terminal 1 (A) should be connected to the power supply's negative terminal. Terminal 2 (B) should be connected to the power supply's positive connection.

Note: Ensure that the power source is adequately fused in order to minimize the possibility of damage if the device should fail. The power source should have an automatic switch so that the power is available only when the engine is started and running.

Thermocouple

Illustration 4	g00310830
Connections At Channel "0"

Channel "0" is used in order to monitor the turbocharger inlet exhaust temperature. This thermocouple's temperature is continuously compared to the operator's temperature setpoint.

Connect the Type K thermocouple extension wire from the turbocharger inlet exhaust temperature's thermocouple to channel "0" of the pyrometer. Connect the Red wire to the upper terminal. Connect the Yellow wire to the lower terminal.

If channel "0" is not going to be used, connect a jumper wire across the input terminals at the rear of the pyrometer.

Illustration 5	g00310887
This Illustration represents the three switch positions for the pyrometer.

For six cylinder in-line engines or eight cylinder in-line engines, connect the Type K thermocouple's extension wire from each thermocouple's sensing source to the back of the pyrometer. Ensure that each of the cylinders is connected to the cylinders' corresponding channel. Ensure that the switch on the pyrometer is selected for the correct cylinders.

For twelve cylinder engines or sixteen cylinder engines, use two pyrometers. Connect all of the cylinders that have odd numbers to one pyrometer. Connect all of the cylinders that have even numbers to the second pyrometer. Ensure that the switch on the pyrometer is selected for the correct cylinders. Connect a jumper wire at the rear of the pyrometer across the input terminals of any channels that were not used.

In order to ensure an accurate signal to the pyrometer from the thermocouples, avoid any unnecessary junctions, splices, and contacts with other metals. Ensure that the insulation of the thermocouple's extension wire is not damaged during installation. Protect the thermocouple's extension wire from vibration, abrasion, and liquids in the conduit.

Place the extension wires in a conduit for added protection. Never put the wires from the thermocouple in the same conduit that is used for wires in a high energy circuit, such as ignition wiring or AC power.

The secondary wires that are connected to high energy circuits should be prevented from contacting the thermocouples and thermocouple wires.

Setpoint Switch

Illustration 6	g00312664

The terminal 4 "coil" that is directly below the "Switch" label is the output of the switch. A high temperature condition on channel "0" actuates an internal switch that is normally open. The switch will also be actuated if the thermocouple for channel "0" is not connected or if the thermocouple for channel "0" becomes an open circuit. Do not leave the thermocouple's signal to channel "0" open. Connect channel "0" to a thermocouple. Channel "0" can also be connected with a jumper wire across the input terminals.

If the pyrometer's "coil" contact is going to be utilized as data or an alarm with a mechanical annunciator panel, this contact should energize a relay, such as the 9Y-2921 Relay .

Connections For The 9Y-2921 Relay

Illustration 7	g00312784
(A) - VDC. (B) + VDC. (C) 9Y-2921 Relay . (D) Terminal "85". (E) Terminal "86". (F) Terminal "87A". (G) Terminal "30". (H) Terminal "87". (I) Annunciator Panel.

Connect the Terminal 4 "Coil" to the relay terminal "86".

Connect the + VDC to the relay terminal "30" and the relay terminal "85".

Connect the relay terminal "87" to the annunciator panel.

The connection at the Terminal 4 "Coil" should be left open when the pyrometer's coil is not being used. Make sure that the thermocouple wire to channel "0" is connected by a jumper wire or connected to a thermocouple.

Operation

Advancing The Channels

Illustration 8	g00312846

Once the pyrometer is powered up, the pyrometer will start reading the temperature of channel "0". In order to read the temperatures of the other eight channels, push the "PUSH TO ADVANCE" switch. The "PUSH TO ADVANCE" switch is located in the middle of the front panel. When the switch is actuated, the pyrometer's readout will increment to the next channel.

Selector Switch

Illustration 9	g00312863

The selector switch is located on the lower left side on the back side of the pyrometer. Set the selector switch to the "IN-LINE" position for six cylinder in-line engines and eight cylinder in-line engines.

For 12 cylinder engines and 16 cylinder engines which use two pyrometers, set the selector switch on one pyrometer to the "V-EVEN" position. Set the other pyrometer to the "V-ODD" position in order to correspond with the thermocouple wires that enter the individual pyrometers.

Setpoint Adjustment

Illustration 10	g00313148

The high temperature alarm setpoint for channel "0" is read by pressing the "PUSH TO READ" button. In order to adjust the setpoint, first press the "PUSH TO READ" button. Next, unscrew the cap from the set point potentiometer. Then adjust the potentiometer setting with a small screwdriver until the display matches the desired temperature. Turn the potentiometer clockwise in order to increase the desired temperature. Turn the potentiometer counterclockwise in order to decrease the desired temperature.

The output switch will be activated when the temperature reading at channel "0" exceeds the desired temperature setting that was set previously.

Note: The setting is retained until the potentiometer setting is changed.

Testing The Thermocouple Leads

Illustration 11	g00313183

Whenever it is necessary to check the wiring of the thermocouple, disconnect the thermocouple's wiring at the back of the pyrometer. This will prevent damage to the pyrometer's sensitive circuitry.

Troubleshooting

1. Thermocouple Wiring Checks

   1. Disconnect the leads from the back of the pyrometer.

   2. Check the resistance of the leads from thermocouple when the thermocouple is connected. A low resistance should be present. The actual value will depend on the length of the leads and the temperature of the thermocouple. If an open circuit is indicated, check the resistance of the thermocouple in order to determine the location of the open circuit. The open circuit could be in the wiring or the open circuit could be in the thermocouple.

2. Blank Display

   1. Check the power supply's voltage at Terminal 1 and at Terminal 2. If the voltage is not between 12 VDC and 125 VDC, repair the power supply. Otherwise, replace the pyrometer.

3. Display Showing Maximum Reading (900°C (1500°F))

   1. This is an indication of an open circuit. If no thermocouple is connected to the channel with this indication, install a jumper wire. If a thermocouple is connected to the channel, refer to the "Thermocouple Wiring Checks".

4. Display Showing Ambient Temperature

   1. This could be an indication of a short circuit in the thermocouple. This could also be an indication of a short circuit in the wiring. Exchange the thermocouples in order to determine if the thermocouple is operating properly. Check the wiring for burnt wires or damaged wires.

5. Display Showing Lower Than Normal Temperature

   1. If the reading is much lower than normal, refer to the "Display Showing Ambient Temperature". If the temperature is slightly lower than normal, ensure that the thermocouple and the thermowell are properly located in the exhaust stream. Make sure that no deposits have built up.

6. If the actual temperature is lower or higher than normal refer to the appropriate engine service manual.