Fluke 5220A 4-22. Front Panel Tests, 4-23. Zero Output

Maintenance

Performance Test

4

4-9

4-22. Front Panel Tests

Use the following procedure to check the operation of the 5220A front-panel controls and

LEDs:

1. With the unit in the standby mode, connect jumper wires between the enabled

(front/rear) output terminals. Use a 4-inch length of 16-gauge insulated wire.

2. Press the OPR/STDBY pushbutton. The OPR LED should light and the STDBY LED

should go out.

3. Press the INPUT pushbutton to select the rear input.

4. Return input control to the front panel by pressing the INPUT pushbutton. The

FRONT LED should light and the REAR LED should go out.

5. Remove the jumper wire from the output terminals. The unit should switch to the

standby mode and the OVERCOMPLIANCE LED should light.

6. Reinstall the jumper wire at the output terminals.

7. Clear the overcompliance condition by pressing the OPR/STDBY switch. Set the unit

to the operate mode.

Caution

The THERMAL CUTOFF LED will light only when the output

stage of the 5220A is overheated. This is a failure mode that

should not be invoked for test purposes. The LOCAL

pushbutton and the REMOTE, LOCAL LOCK OUT LEDs are

remote control features that require remote commands for

operation.

4-23. Zero Output

The following procedure checks the zero output of the 5220A in both the standby and

operate mod es:

1. Connect the load resistor (0.1 ohm) to the enabled (front/rear) output terminals.

2. Connect the DVM to the sense terminals on the load resistor and select the 100 mV

dc range.

3. With the 5220A in the standby mode, read the voltage drop across the load resistor.

The reading should be 0 +/-5 µV dc.

4. Connect a short jumper wire between the front VOLTAGE INPUT terminals.

5. Set the 5220A to the operate mode. The OPERATE LED should be on and the

STANDBY LED off.

6. Read the output voltage on the DVM. It should be 0 +/-100 µV dc.

7. Set the 5220A to standby and remove the jumper wire from the VOLTAGE INPUT

terminals.

8. Disconnect the load resistor from the output terminals on the 5220A.

Contents

Main Page Table of Contents 5220A Page Page List of Tables Page List of Figures 5220A Page Page Section 1 Introduction and Specifications 1-1. Introduction 1-2 1-2. Specifications Specifications for the Model 5220A are given in Table 1-2. Introduction and Specifications Specifications 1-3 1-4 Page Page Section 2 Operating Instructions 2-1. Introduction 2-2. Shipping Information 2-3. Input Power 2-4. Fuse Replacement 2-5. AC Line Fuse 2-6. Power Supply Fuses 2-7. Rack Installation 2-8. Operating Features Page 5220A 2-4 2-9. Operating Notes 2-10. AC Line Connection 2-11. Transconductance Amplifier 2-12. Input Voltage Requirements 2-13. Input Voltage Selection, Front/ Rear 2-14. Current Output, Front/Rear 2-15. Standby/Operate 2-16. Local/Remote 2-17. Status Indicators 2-18. Audible Output 2-19. Inductive Loads Page 2-20. Operation Page Section 3 Theory of Operation 3-1. Introduction 3-2 . Overall Functi onal Descri ption 3-3. General 3-4. Analog Section Page Page 3-5. Digit al Section 3-6. Circuit Analysis 3-7. Power Supply Page 3-8. Preamplifier 3-9. A6 Driver Page 3-10. A7 Output 3-11. A8 Analog Control 3-12. A9 Front Panel 3-13. A10 Logic 3-14. Reset Logic Page 3-15. Timing Logic 3-16. Standby/Operate Logic 3-17. Local/Remote Logic 3-18. Front/Rear I nput Logic 3-19. Failure Status Logic 3-20. A11 MIS Bus Interface Page Page Section 4 Maintenance 4-1. Introduction WWarning 4-2. Service Information 4-3. General Maintenance 4-4. Cleaning 4-5. Air Filter Maintenance 4-6. Access Information Page 4-7. Internal Components/Assemblies 4-8. Front Panel Removal 4-9. A9 Front Panel PCB Removal 4-10. A2 Transformer Assembly Removal 4-11. A6 Driver and A7 Output Assembly Removal 4-12. A3 Cap Bus Removal 4-13. A12 Shunt Assembly Removal 4-14. Fuse Replacement 4-15. Ac Line Fuse 4-16. Power Supply Fuses 4-17. Line Voltage Selection 4-18. Output Terminal Selection, Front/Rear 4-19. Service Tools 4-20. Performance Test 4-21. Initi al Conditions 4-22. Front Panel Tests 4-23. Zero Output 4-24. DC Accuracy and Line Regulation 4-25. Harmonic Distortion 4-26. Frequency Response 4-27. Overcurrent Trip Test 4-28. Overvoltage Trip Test 4-29. Calibration Adjustments 4-30. Initi al Conditions 4-31. Input Offs et Adjustment 4-32. Driver Offset Adjustment 4-33. Output Bias Adjustment 4-34. DC Accuracy Adjustment 4-35. Frequency Response 4-36. Overcurrent Adjustment 4-37. Overvoltage Adjustment 4-38. Replacement of Selecte d Components 4-39. Resistors R11 and R12 4-40. Resistor R13 4-41. Troubleshooting h Page Page 4-21 4-22 Note The jumper wire must be installed between the enabled output terminals. 4-23 Page 4-25 4-26 Section 5 List of Replaceable Parts 5-1. Introduction 5-2. How to Obtain Parts 5-3 . Manual St atus Information 5-4. Newer Instruments 5-5. Service Centers W Page Page 5-5 5-6 5-7 Page Page Page Page Page Page Page Page Page 5-17 5-18 5-19 Page 5-21 Page 5-23 5-24 Page 5-26 5-27 5-28 h Indicates a static-sensit ive part. Page Page 5-31 Page 5-33 Page Page Page Page 5-38 Note The A12 shunt assembly is a suggested non-repairable assembly. Page 5-40 5-41 Page Section 6 Option and Accessory Information 6-1. Introduction 6-2. Accessories 6-3. Rack Mounting Kit (M08-205-600) Page 6-4. Rack Slide Kit (M00-280-610) 6-5. Precision Y5020A Current Shunt