KEPCO KLR Series User Manual - Manual (Page 32)

2-8
KLR 091313
2.7.1 SAFETY GROUNDING
Local, national and international safety rules dictate the earth grounding of the metal cover and
case of any instrument connected to the a-c power source, when such grounding is an intrinsic
part of the safety aspect of the instrument.
KLR is provided with a three-terminal IEC appliance coupler for connection of the mains supply
source, one terminal of which is dedicated for the protective earthing conductor; no other ground
or earth connection is required, although the chassis may be separately connected to earth
ground for noise or other performance considerations (frame grounding).
The instructions below suggest wiring methods which comply with these safety requirements;
however, in the event that the specific installation for the power system is different from the rec-
ommended wiring, it is the customer's responsibility to ensure that all applicable electric codes
for safety grounding requirements are met.
2.7.2 SOURCE POWER
2.7.2.1 CURRENT RATING
All switchmode power supplies, including the KLR series, present a constant power characteris-
tic to the input power source. Consequently, the power supply draws maximum input current for
a given load power at low input voltage, and proportionately less as source voltage is raised
according to the formula
Input Current = Output Power / (Efficiency x Input Voltage)
The input power circuit breaker of the power supply is rated to support rated load power under
worst-case efficiency conditions at the lowest rated source voltage (180V a-c), and provides the
necessary overload protection to the power supply's internal circuitry. The user must provide a
properly sized and rated mains lead (line cord) and service with a current rating compatible with
the anticipated input current.
Operation at rated load power (2400W) over the full rated source voltage range (180 - 265V a-c)
requires a branch service rating of 20 Amperes; Kepco recommends use of #12 AWG (2,0 mm
2 )
for primary wiring. For operation at output power of 2000W or less, or with source voltage not
less than 200V a-c, branch service may be reduced to 15 Amperes using #14 AWG (1,6 mm
2
)
wiring. Contact Kepco Applications Engineering for details.
For continuous operation at output power levels lower than 2000 watts, or for other line cord
styles, contact Kepco Applications Engineering for additional options.
2.7.2.2 CONNECTIONS
Source power is connected at the rear panel of the KLR power supply (see Figure 2-2) via the
IEC 320-style recessed power inlet connector, which provides interface to a three-wire safety
line cord via a polarized mating plug. A user-wirable mating connector is provided. Terminal
assignment follows internationally accepted conventions. It is the user's responsibility to ensure
that all applicable local codes for source power wiring are met. Kepco also makes a variety of
prefabricated safety line cord sets available for connecting KLR to source power via conven-
tional box-mounted receptacles. Table 1-5 lists three popular cord set variants for North Ameri-
can applications. For other options please contact Kepco Sales Engineering with specific
requirements.