KEPCO HSM Series - Manual (Page 15)

HSMSERIES OPR 052912
2-3
2.3 SOURCE POWER REQUIREMENTS
This power supply will operate with the installed fuse from single phase a-c mains power over
the specified voltage and frequency ranges without adjustment or modification. Operation from
d-c power is also available; please contact factory for limitations imposed when using d-c
source power.
2.4 COOLING
The power devices used within the HSM power supply are maintained within their operating
temperature range by means of internal heat sink assemblies cooled by an internal cooling fan.
The cooling method utilizes pressurization rather than evacuation, resulting in greater cooling
efficiency and reduced contaminant collection within the enclosure. ALL INLET AND EXHAUST
OPENINGS AROUND THE POWER SUPPLY CASE MUST BE KEPT CLEAR OF OBSTRUC-
TION TO ENSURE PROPER AIR ENTRY AND EXHAUST. Periodic cleaning of the power sup-
ply interior is recommended. If the power supply is rack mounted, or installed within a confined
space, care must be taken that the ambient temperature, which is the temperature of the air
immediately surrounding the power supply, does not rise above the specified limits for the oper-
ating load conditions (see PAR. 1.3 and Figure 1-2).
2.5 PRELIMINARY OPERATIONAL CHECK
A simple operational check after unpacking and before equipment installation is advisable to
ascertain whether the power supply has suffered damage resulting from shipping. Refer to Fig-
ures 2-1 and 2-2 for location of operating controls and electrical connections.
1. THE POWER SUPPLY WILL NOT OPERATE UNLESS THE REMOTE SENSE LINES ARE
PROPERLY CONNECTED TO THE OUTPUT TERMINALS! Connect the remote sense ter-
minals to the output bus bars using the mating I/O Connector (Kepco P/N 142-0422) or other
means as shown in PAR. 2.7.5.1 and Figure 2-3.
2. Connect the power supply to source power as defined in PAR. 1.3. Connection can be made
using either the North American linecord set (Kepco P/N 118-0776) or using a custom line-
cord terminated at one end with an IEC 320/C19 plug (Kepco P/N 142-0381). Follow all
requirements of local electric code regarding wire size, termination, etc.
3. Connect a static load, R, across output terminals. The load value is determined by the nomi-
nal output voltage of the HSM power supply and must be capable of handling 2% of the
power supply output rating (minimum power capability of 20 watts). R is calculated as
approximately equal to output voltage
2
/20 (R = E
2
/P). For example, for the HSM 48-21, R =
48
2
/20 = 115.2; use load of 120 ohms, 20 watts.
4. Apply source power; using a DVM, measure the voltage across the output bus bars; this volt-
age is factory set to the value shown in PAR. 1.3. If necessary, adjust the output voltage
using the trim pot labeled "V
O
" accessed through the top cover.
5. Using the DVM, measure the voltage across I/O connector pins 38 and 19; this voltage
should read
1
/
10
of the output voltage measured in step 4 above, ±1%.
6. Using the DVM, measure the voltage across I/O connector pins 33 and 19; this voltage is
factory adjusted to 10.0V, and corresponds to 100% of maximum current (see PAR. 3.7). If
necessary, readjust to 10.0V using the trim pot labeled “I
MAX
” accessed through the top
cover; if desired, readjust for lower current limit (see PAR. 3.7).