Page 5
DPS
12. Use VOLTAGE ADJUST potentiometer to select
output voltage desired. Disconnect voltmeter from
terminal blocks, and re-connect leads to “+T” and
“–T” test jacks on front panel of DPS 240.
13. Verify that reading at these test jacks is the same
as for terminal block connections.
14. Remove ac input, and dismantle test setup.
The unit is now calibrated and ready to be placed into
service.
Installation
Installing the DPS 240 consists of physically mounting
the device, and then completing the necessary electri-
cal connections.
Mounting
Although the DPS 240 is designed to employ convec-
tion cooling, it is advised to mount it on a surface
made of material that can serve as a heat sink. Care
should also be taken to locate the DPS 240 in an area
that is protected from dust, moisture, and corrosive
atmospheres.
Figure 2 shows the outline dimensions of the DPS
240.
To mount the unit, the DIN rail should be positioned so
that the smaller of its two flanges is toward the top
(see figure 2).
Tilt the unit slightly backward, and insert the spring
flanges on the back panel under the top flange of the
DIN rail. Push inward and down until the DPS 240
snaps into place.
To remove the unit, pull outward (from the bottom)
and up.
Calibration Procedure
To calibrate the DPS 240:
1. Turn CURRENT LIMIT potentiometer fully clock-
wise.
2. Vary setting of VOLTAGE ADJUST potentiometer
from fully clockwise to fully counterclockwise.
Note output reading at each extreme. Available
voltage range will equal ±5.0% of unit’s rated out-
put voltage (23.8 to 25.2 Vdc for 24-Vdc models,
or 39.9 to 44.1 Vdc for 42-Vdc models).
3. Use VOLTAGE ADJUST potentiometer to set out-
put voltage to maximum specified for the unit be-
ing calibrated, ±10 millivolts (24, or 42 Vdc, as
appropriate).
4. Reset load to 91ý, or until the milliammeter reads
264 mA (+10% of the maximum rated current out-
put for the DPS 240).
5. Turn CURRENT LIMIT potentiometer counter-
clockwise until output voltage drops to 23.88 Vdc
for 24 Vdc units, or 41.79 Vdc for 42 Vdc units
(99.5% of appropriate nominal output level ).
6. Reset load so that current output is 240 mA.
7. Short the output.
Red “OUTPUT ON” LED on unit’s front panel will
go out.
8. Hold short circuit in place for 1 minute, then re-
move it. Observe that the LED turns on, and that
output voltage quickly returns to rated nominal,
±10 mV (23.88 Vdc for 24-Vdc units, or 41.79 Vdc
for 42-Vdc units).
9. Remove load. Observe that output voltage drop is
less than 100 mV.
10. Re-apply load. Set it so that current output is 240
mA. Note output voltage reading at this setting.
11. Vary input voltage ±10%. Observe that voltage
varies less than 0.5%, low-line to high-line.
Summary of Contents for DPS 240
Page 10: ...NOTES...
