Panametrics DigitalFlow GM868, Service Manual

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DigitalFlow™ GM868 Service Manual 29
Chapter 4. Parts Replacement
Chapter 4. Parts Replacement
4.1 Introduction
The electronics console of the Model GM868 has been designed to permit easy on-site upgrades and parts
replacement. See Figure 8 on page 39 and Figure 9 on page 40 for details of the standard GM868 electronics console
assembly. The instructions in this chapter, along with a few common tools, are all that is required to perform the
following tasks:
•
fuse replacement
• printed circuit board (PCB) removal and installation
• EPROM replacement
• option card installation
• LCD display replacement
IMPORTANT: For meters supplied in any of the optional enclosure types, see Appendix B, Optional Enclosures, for
instructions specific to that unit.
Note: For compliance with the European Union’s Low Voltage Directive, this unit requires an external power
disconnect device such as a switch or circuit breaker. The disconnect device must be marked as such,
clearly visible, directly accessible, and located within 1.8 m (6 ft) of the Model GM868. The power cord is the
main disconnect device.
An aluminum shroud over the printed circuit board shields the electrical components and serves as a location for the
wiring diagram label. All of the procedures discussed in this chapter, except for fuse replacement, require removal of
this shroud.
Note: For compliance with the European Union’s Low Voltage Directive, a transparent plastic shroud protects the
electrical connections. The shroud must remain in place, except while wiring the unit. Reinstall the shroud
after the wiring has been completed.
Use the foldout drawings at the end of this chapter to locate the relevant components, while completing the
following procedures.
IMPORTANT: Keep a detailed record all service procedures performed on the Model GM868 in Appendix A, Service
Record. This service history may prove very helpful in diagnosing any future problems.
WARNING!
Prior to performing any maintenance procedures, be sure to disconnect the main
power from the unit.