AMETEK CW-M - Manual (Page 18)

Elgar CW-M Series
3-2 M161570-01
If the instrument needs to be returned to Elgar, suitable shipping
containers and packing materials must be used. If proper packing material
is not available, contact Elgar to provide containers and shipping
instructions.
Before shipping a product to Elgar, you must obtain a Return Material
Authorization (RMA) number from Elgar’s Repair Department. See the
warranty page at the front of this manual for details.
3.2 WIRE GAUGE SELECTION
The following guidelines assist in determining the optimum cable
specification for your power applications. These guidelines are equally
applicable to both DC and low frequency AC (up to 450 Hz) power cabling.
The same engineering rules apply whether going into or out of an electrical
device. Thus, this guide applies equally to the input cable and output cable
for this Elgar instrument and application loads.
Power cables must be able to safely carry maximum load current without
overheating or causing insulation destruction. It is important to everyday
performance to minimize IR (voltage drop) loss within the cable. These
losses have a direct effect on the quality of power delivered to and from
instruments and corresponding loads.
When specifying wire gauge, the operating temperature needs to be
considered. Wire gauge current capability and insulation performance
drops with the increased temperature developed within a cable bundle and
with increased environmental temperature. Thus, short cables with
generously derated gauge and insulation properties are recommended for
power source applications.
Avoid using published commercial utility wiring codes, which are designed
for the internal wiring of homes and buildings. Although these codes
accommodate the safety factors of wiring loss, heat, breakdown insulation,
aging, etc., they consider that up to 5% voltage drop is acceptable. Such a
loss directly detracts from the quality performance specifications of this
Elgar instrument. Frequently, these codes do not consider bundles of wire
within a cable arrangement.
In high performance applications, as in motor start-up and associated
inrush/ transient currents, additional consideration is required. The cable
wire gauge must consider peak voltages and currents that may be up to
ten times the average values. An underrated wire gauge adds losses that
alter the inrush characteristics of the application and thus the expected
performance.