In a switch the least reliable module is the fan and PSU.

The fan problem can be reduced by using good quality components and to operate fans in parallel.
The fan usually becomes noisy before complete failure so there normally is time to replace it.

    The PSU is highly stressed both by transients and temperature. The PSU itself has filters mainly
 for EMC but they also offer some transient protection.
    If the operating temperature of the PSU can be reduced then the reliability will be significantly
increased. This can be achieved by either de-rating the PSU or dueling PSU's such that they 
supply half the full current each but supply the full current should the other fail. The system reliability
is then further enhanced as the probability of the second PSU failing before replacement of the faulty 
unit is very low.

    VolAmp Ltd has now introduced a load share chassis into its range to cater for the requirement for
high reliability. The chassis incorporates two PSU's and a load share monitor circuit. Should any supply
fail then an audible signal is emitted and the faulty PSU can be replace at a convenient time.
The monitor circuit identifies the faulty supply via LED's which are visible once the lid is removed.

The chassis have been designated as =

B8-LS		for 8 port switch
B16-LS		for 16 port switch
B24-LS		for 24 port switch

Physically the Load Share chassis is identical to the normal single supply unit.

VolAmp Ltd

  Unit 3, Riverside Business Park, Dogflud Way, Farnham, Surrey, GU9 7SS

  Tel 01252 724055 Fax 01252 733425 E-mail: info@volamp.com

  www.volamp.com