Symmetricom 5401 User Manual

Page of 40
PN 8500-0150, Rev. A, May 2005
5
Operating Manual
Installation
Symmetricom 5402 Rack Mounting Procedure 
The 5402 is designed for standard nineteen-inch rack mounting. 
Optional chassis slides are recommended if the unit is to be installed in an equipment rack. If 
slides are not used, a supporting bar or tray should be provided for the rear of the instrument. 
The chassis slides attach to the sides of the 5402. To mount the slides, use six # 8/32 screws, 
1/2 inch long (three on each side). 
Caution: If the 5402 is mounted in a rack by merely attaching the front panel to the 
RETMA rails, with no rear chassis support, the front panel will warp and eventually break. 
General Cautions/Hazards to be considered when installing the 5402 Timing Unit into an 
equipment rack include: 
TMRA - The maximum recommended ambient temperature (TMRA) that this equipment 
is specified to operate in is 50ºC. 
Elevated Operating Ambient Temperature - If installed in a closed or multi-unit rack 
assembly, the operating ambient temperature of the rack environment may be greater 
than room ambient. Therefore, consideration should be given to installing the equipment 
in an environment compatible with the maximum rated ambient temperature (TMRA). 
Reduced Air Flow - The equipment has no cooling fans and depends on convection for 
cooling. Installation in a rack may cause an excessive heat rise if sufficient air flow is not 
available. Installation should be such that the amount of air flow required for safe opera-
tion of the equipment is not compromised. 
Mechanical Loading - Mounting of the equipment in the rack should be such that a haz-
ardous condition is not achieved due to uneven mechanical loading. 
Circuit Overloading - Consideration should be given to the connection of the equipment 
to the supply circuit and the effect that overloading of circuits might have on over current 
protection and supply wiring. Appropriate consideration of equipment nameplate ratings 
should be used when addressing this concern. 
Reliable Earthing - Reliable earthing of rack-mounted equipment should be maintained. 
Particular attention should be given to supply connections other than direct connections 
to the branch circuit (e.g., use power strips).