NCR 7448 Workstation, Site Preparation Manual

Page: 59 / 61

Appendix A: Transient Protection
AC Power Line Transient Protection
In the process of power distribution, transient electrical energy (including, but
not limited to, lightning strikes, intermittent short circuits, and switching
transients) can be introduced onto power lines. Such transient energy can be
very damaging to electronic hardware, and can also cause data corruption.
Under these circumstances, NCR recommends the use of AC power transient
suppressors. Such protection devices are intended to guard against power line
transients that can result in hardware damage and various system or program
errors.
Improvement of any deficiencies in power quality is a customer responsibility.
Malfunction and/or component failure as a result of power quality problems
are/is not covered by the NCR Maintenance Agreement. NCR accepts no
liability for any such occurrence not for its consequences.
When power transient suppression is required, the suppressors used should meet
the following minimum requirements:
•
Dissipate energy to match the appropriate application categories as defined
by IEEE Standard 587.
•
Be aware of the voltage limiting (clipping), or tracking filter type. The
suppressor must not clamp the voltage to zero, and must self-recover after the
passage of the transient. The suppressor may be of the hybrid type
construction that makes use of various technologies in order to meet speed
and dissipation requirements.