AMETEK DLM 600W Series - Manual (Page 33)

DLM 600W Series
M362161-01 Rev J 2-9
2.9 Load Connections
Low–voltage models rated 5V–60V have bus bars at the rear of the unit for connecting
the load; refer to Figure 3-1. The bus bars are protected with a two–piece cover. The
top portion of the cover is removable to allow access to the bus bar screws. In addition,
the top portion has scored sections at the top and back that could be removed to
provide a larger opening for wiring.
Ensure that wires are routed appropriately to prevent shorting, and that the cover is
properly installed before applying AC power to the unit. For applications where the bus
bars are not operator accessible, such as rack mounting, both portions of the cover
could be removed. Ensure that adequate protection from accidental contact is provided
for service personnel that might work on the equipment.
High–voltage models rated 80V–300V have an output terminal block with a snap–on
cover. Ensure that the cover is in place, and that it insulates all connections to the
output terminals before operating the unit.
WARNING
To prevent electrical shock, disconnect the AC power cord before
making any connections to the unit.
CAUTION
If longer bus bar screws are substituted, ensure that a clearance
of at least 0.125” (3.2 mm) exists to the rear panel to prevent an
electrical short.
When connecting the load to the power supply, consider the following factors to select
a suitable wire gauge: the current carrying capacity of the wire (limited by temperature
rise of the wire); the voltage drop across the total length of load lines; noise coupling
and impedance effects of the load lines.
2.9.1 Wire Current Carrying Capacity
Load wiring must have a current carrying capacity greater than the output current rating
of the power supply. This ensures that the wiring will not be damaged even if the load is
shorted.
Table 2–2 shows the current rating, based on 500A/cm
2
, for various gauges of wire.
The maximum current that a particular wire can conduct is dependent on multiple
factors: ambient temperature, temperature rating of insulation, wire bundling, and
altitude. The primary constraint is that the temperature rise of the wire resulting from
the current flow, added to the ambient temperature, must not exceed the maximum
operating temperature of the insulation.