Fluke 875 manual ESC Board P/N 876A-1-92, Schematic 876A-1-3D

Page 37

Maintenance, Calibration, and Troubleshooting	5
Muting Stages of the Alarm Circuits

Conversely, during the ECS Test muting is definitely wanted, and the +12 V on pin 9 can easily overcome the +2 V on pin 10.

5.10ESC Board (P/N 876A-1-92, Schematic 876A-1-3D)

The wave-shapes shown in Figure 5-1 should be sufficient for localization of malfunction on the ECS board. Test points A to S are shown on 876A-1-3D. The wave-shapes at the lettered test points are drawn to the same time scale and also synchronized in time.

The wave-shape at the top of Figure 5-1 is the output at TP201. It is the main synchronizing waveshape for the lettered wave-shapes, but it is drawn to a different time scale.

These wave-shapes are best used in connection with the discussion of the ECS circuitry.

CAUTION

Electrostatic discharge precautions should be followed when servicing the ECS board, due to the MOS FET devices located on it.

5-7

Image 37

Contents High Range Containment Monitor VictoreenFluke Biomedical Table of Contents Calibration and Test Procedures Introduction SpecificationsGeneral Description Containment MonitorReadout Module 876A-1 Temperature Operating 40 to 120F 4 to 49CHigh-Range Containment Monitor Detector Equipment OverviewRack Chassis Cables/Connectors/Panel Pull Box AssemblyFlexible Tubing 878-12-30TAB Optional EquipmentHigh-Range Containment Monitor Typical Energy Response Curve Detector Typical Linearity Detector Receiving Inspection High-Range Detector, Recommended InstallationStorage Procedures, Warnings, and CautionsBlank Installation InstallationReadout Module Pull BoxCable Sealing Specifications for CableDetector Test After Installation Cable and Wiring InstallationSpecifications for Cable Detector Cable Inside ContainmentAll Alarms on P2 Normal Operation Shelf State Ancillary WiringPower Connections P1 Computer & RecorderOperation OperationVictoreen Functional Description Function DescriptionReadout Module 876A-1 Negative Power Supply FAIL/SAFE Comparison Circuit on Power Supply Board High Voltage Power Supply Normal Operation non-ECS TestOperation of High Voltage Supply During ECS Test Alert Alarm Circuit High Alarm CircuitRecorders and Computer Buffers Fail/Safe CircuitPen Clamp Meter at extreme lower end of scale Panel Meter Action During ECS TestLow Voltage Ramp Generator Action of Green Safe/Reset Light and Alarm During ECS TestMonitoring Circuits of The ECS Board Block Diagram of ECS Test Muting Circuits of ECS Board Safe/Reset Sub-circuitsBlank Maintenance Maintenance, Calibration, and TroubleshootingCalibration Test Procedure TP876A-1-108 Troubleshooting Mother Board P/N 876-1-78, Schematic 876-1-3A Signal Input CircuitPreamplifierIMeter Board P/N 876A-1-86, Schematic 876A-1-3E Rear PanelTest Point Normal Channel Test TP501 TP502 +6.3Muting Stages of the Alarm Circuits High Alarm CircuitNormal Low Signal Level Channel Test ESC Board P/N 876A-1-92, Schematic 876A-1-3D Wave Shapes on the Electronic Check Source Board Overall Fail Circuitry Associated with the ECS Test Starting With Pins M and P on the Power Supply SchematicStarting With Terminal H on Relay Driver Board Operation of the Latch Circuit Outputs of U206 Pulse Generator on the ECS BoardCircuit assumed initially in Pass Condition Fail Condition Latch CircuitPin Voltage State Comments NORCalibration and Test Procedures Blank Cable and Pull Box Procedures Cable and Pull Box ProceduresVictoreen Applicable Drawings Applicable Drawings and Bill of MaterialsDocument Number Description Detector Cable Out of Containment Applicable Bill of Materials Fluke Biomedical