Installation and Service Guide N5251-90001 1-3
PNA Series Microwave Network Analyzer System 
N5251A
    Safety and Regulatory Information 
General Safety Considerations
The opening of covers or removal of parts ma
y expose dangerous voltages. 
Disconnect the instrument from all voltage sources while it is opened.
Danger of explosion if battery is incorrectly replaced. Replace only with 
the same or equivalent type recommended. Discard used batteries 
according to manufacturer’s instructions.
Procedures  described  in  this  document  may  be  performed  with  power 
supplied  to  the  product  while  protective  covers  are  removed.  Energy 
available at many points may, if contacted, result in personal injury.
The power cord is
 connected to internal capacitors that may remain live for 
10 seconds after disconnecting the plug from its power supply. 
For continued protection against fire hazard, replace line fuse only with same 
type and rating. The use of other fuses or material is prohibited.
The detachable power cord is the instrument disconnecting device. It 
disconnects the mains circuits from the mains supply before other parts of the 
instrument. The front panel switch is only a standby switc
h and is not a LINE 
switch (disconnecting device).