BRUSH AS 3T4703 - Caterpillar

Test Procedure
System Operation
Transducers convert pressures to an electric current signal. A transducer's signal is linearly proportional to the value of the parameters.The signal is routed from the engine mounted junction box to terminals in the MECP. The PLC routes the signal to an input module. The input module converts the signal into the parameter.The signal is used in order to trigger alarms and the signal is used in order to display the parameter.
Illustration 1 g00563605
Illustration 2 g00563611
Illustration 3 g00563600
Schematic of the transducerFunctional Test
Check the electrical connectors and check the wiring.
Bodily contact with electrical potential can cause bodily injury or death.To avoid the possibility of injury or death, ensure that the main power supply has been disconnected before performing any maintenance or removing any modules.
Disconnect the power supply.
Check the electrical connectors and check the wiring for damage or bad connections.
Verify that all modules are properly seated.
Verify the status of the LED on the SLC 5/04.The results of the preceding procedure are in the following list:
All of the components are fully installed. All of the components are free of corrosion. All of the components are free of damage. All of the modules are properly seated. Proceed to 2.
The components are not fully installed. The components are not free of corrosion. The components are damaged. All of the modules are not properly seated. Repair the component. Verify that the repair resolves the problem. STOP.
Monitor the transducer with an ammeter.
Illustration 4 g00563603
Diagram of the ammeter connection
Connect an ammeter in the circuit. See illustration 4.
Monitor the ammeter for the correct output of the transducer. See table 1 for the transducer's information.
Table 1
Current (mA)     141-9880 Transducer (1)     141-4003 Transducer (2)    
4.0    
0 kPa ( 0.0 psi)    
0 kPa (0.0 psi)    
4.5    
31.3 kPa (4.5 psi)    
125.0 kPa (18.1 psi)    
5.0    
62.5 kPa (9.1 psi)    
250.0 kPa (36.3 psi)    
5.5    
93.8 kPa (13.6 psi)    
375.0 kPa (54.4 psi)    
6.0    
125.0 kPa (18.1 psi)    
500.0 kPa (72.5 psi)    
6.5    
156.3 kPa (22.7 psi)    
625.0 kPa (90.6 psi)    
7.0    
187.5 kPa (27.2 psi)    
750.0 kPa (108.8 psi)    
7.5    
218.8 kPa (31.7 psi)    
875.0 kPa (126.9 psi)    
8.0    
250.0 kPa (36.3 psi)    
1000.0 kPa (145.0 psi)    
8.5    
281.3 kPa (40.8 psi)    
1125.0 kPa (163.1 psi)    
9.0    
312.5 kPa (45.3 psi)    
1250.0 kPa (181.3 psi)    
9.5    
343.8 kPa (49.8 psi)    
1375.0 kPa (199.4 psi)    
10.0    
375.0 kPa (54.4 psi)    
1500.0 kPa (217.5 psi)    
10.5    
406.3 kPa (58.9 psi)    
1625.0 kPa (235.6 psi)    
11.0    
437.5 kPa (63.4 psi)    
1750.0 kPa (253.8 psi)    
11.5    
468.8 kPa (68.0 psi)    
1875.0 kPa (271.9 psi)    
12.0    
500.0 kPa (72.5 psi)    
2000.0 kPa (290.0 psi)    
12.5    
531.3 kPa (77.0 psi)    
2125.0 kPa (308.1 psi)    
13.0    
562.5 kPa (81.6 psi)