Smoke exhaust – it’s serious
maintenance engineer; this can render the entire system
unserviceable, depending on where the cable fault occurs.
Cognisance of all possible system faults must be addressed
when selecting equipment and components to deliver a
working SHEVS system.
One would never try to fill a 150mℓ wine glass with a
750mℓ bottle of wine; how is it possible for a designer to
select a 12-amp panel to power a 16-amp ventilator load?
It does not have any bearing on the information produced
by the supplier indicating internal testing regimes. The
panel needs to be certified to meet the claims made. Live
system testing in a workshop is not comparable to testing
in a certified test house. The impact is worse when making
assumptions without certification when it comes to large-
scale fan exhaust systems where cable performance in live
commissioning tests at ambient temperatures negate the
effect of elevated temperatures on the current-carrying
capacity of the same cable at elevated temperatures. The
excessive volt drop impedes current flow, which causes
excessive lower voltage being supplied to the motor,
74
RACA Journal I January 2019
resulting in motor failure. Caution and diligence are required
for all things electrical.
Cognisance of all possible
system faults must be addressed
when selecting equipment and
components to deliver a working
SHEVS system.
Every system designer should safeguard against equipment
without certified documentation supporting the claims
relating to the equipment performance. Time constraints
leading to hasty, inadequately researched solutions always
find enough time to nitpick at decisions made, after an event.
Additional time spent ensuring fit for purpose, suitably
certified equipment saves disasters from occurring and hours
of unproductive time. RACA
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