To Replace The Primary Fuses - Agilent Technologies 5977B Series Operating Manual

1 Introduction

To Replace the Primary Fuses

Materials needed
• Fuse, T12.5A, 250 V (2110-1398) – 2 required
• Screwdriver, flat-blade (8730-0002)
The most likely cause of primary fuse failure is a problem with the foreline
pump. If the primary fuses in your MSD fail, check the foreline pump.

Procedure

1 Vent the MSD, and unplug the power cord from the electrical outlet.
Never replace the primary fuses while the MSD is connected to a power source.
WA R N I N G
If you are using hydrogen as a carrier gas or for the JetClean system, the hydrogen
WA R N I N G
gas flow must be off before turning off the MSD power. If the foreline pump is off,
hydrogen will accumulate in the MSD and an explosion may occur. Read
Safety"
2 Turn one of the fuse holders counterclockwise until it pops out. The fuse
3 Remove the old fuse from the fuse holder.
4 Install a new fuse in the fuse holder.
5 Reinstall the fuse holder.
32
If one of the primary fuses has failed, the MSD will already be off, but for
safety, switch off the MSD and unplug the power cord. It is not necessary to
allow air into the analyzer chamber.
on page 23 before operating the MSD with hydrogen gas.
holders are spring loaded. (See Figure 2 on page 33.)
5977B Series MSD Operating Manual

"Hydrogen