Panametrics GF868, Руководство по обслуживанию

Страница: 43 / 68

DigitalFlow™ GF868 Service Manual (1 and 2-Channel) 35
Chapter 4. Parts Replacement
4.7 Installing the Printed Circuit Board (cont.)
1. Position the printed circuit board within the electronics console with the top edge tilted forward. Insert the display
ribbon cable and keypad ribbon cable connectors into their sockets on the rear of the printed circuit board. See
Figure 8 on page 37 and Figure 9 on page 38 to identify the cables and sockets. Note that the keypad cable
connects to the upper socket and the display cable connects to the lower socket.
IMPORTANT: The ribbon cables must be installed with the edges that were marked during removal oriented toward
the top of the printed circuit board.
2. Carefully position the printed circuit board up against the eight standoffs in the enclosure. Do not damage the
transformers and any installed option cards as they are maneuvered between the standoffs.
3. Loosely install the three long standoffs on the right side of the printed circuit board and the two standoffs (or
screws) along the bottom edge of the printed circuit board.Then, install only the top and bottom short standoffs
on the left side of the printed circuit board.
4. Insert the free end of the green grounding strap between the printed circuit board and the middle standoff
beneath the left side of the board. Making sure to capture the grounding strap lug between the printed circuit
board and the standoff beneath it, install the remaining short standoff on the left side of the printed circuit board.
Securely tighten all eight standoffs and/or screws.
IMPORTANT: Correctly installing the grounding strap may require some patience, but resist the temptation to place
the grounding strap on top of the printed circuit board.
5. Connect the twisted-pair backlight cable to socket J2 on the left edge of the printed circuit board. This plug is
polarized so that it can only be installed in the proper orientation, with the black wire above the red wire.
6. Check for and remove any loose hardware that may have fallen into the electronics console during the
maintenance procedure.
7. Place the main shroud over the six upper standoffs on the printed circuit board. Making sure that the shroud is
oriented with the wiring diagram label upright, fasten the shroud to the standoffs with the six sets of screws and
washers.
8. Reconnect the power line wires and the PC board ground wire to terminal block TB1 on the printed circuit board.
Plug all other electrical connectors into the appropriate sockets on the printed circuit board and option cards.
See Chapter 1,
Installation, of the Startup Guide for instructions on proper wiring of the Model GF868.
Note: For an LVD compliant meter with the clear plastic shroud over the electrical connectors, there will be
standoffs in the two mounting locations along the bottom edge of the printed circuit board. For meters not
equipped with this shroud, there will be Phillips head screws in these two locations.
9. For LVD compliant units, position the clear plastic LVD shroud over the electrical connections so that the two holes
in the shroud align with the standoffs on the printed circuit board. Secure the shroud to the standoffs with the two
sets of screws and washers.
10. After carefully checking for and removing any loose hardware in the enclosure, close the electronics console and
reconnect the main power to the Model GF868.
Note: For compliance with the European Union’s Low Voltage Directive (73/23/EEC), 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 GF868.The power cord is the
main disconnect device.