KEPCO MBT Series - Manual (Page 50)

3-12
MBTSVC111609
3.2.1.6.2 USING VADJ AND NUMERIC KEYS — MR, MGR MODELS
The Vadj and numeric keys can be used to adjust either output voltage or voltage limit (either
the actual value or the programmed value). The effect of the numeric keypad entries is depen-
dent upon the model, the previously commanded mode, whether the output is enabled or dis-
abled, and the load value.
For MR and MGR models, when the output is disabled, the load is disconnected from the power
supply if the power supply is operating in Voltage mode, or the power supply output is short
circuited if the unit is operating in Current mode.
If the output is enabled, the power supply can operate either in voltage mode or current mode,
as determined by both the programmed output values (Voltage or Current) and the value of the
load. If the power supply is commanded to be in Voltage mode, the power supply will actually
operate in voltage mode when R
L
≥ V
Prog
/ I
Prog
, and current mode (forced) when R
L
< V
Prog
/
I
Prog
. Similarly if the power supply is commanded to be in Current mode, the power supply will
actually operate in Current mode when R
L
< V
Prog
/ I
Prog
, and in Voltage mode (forced) when
R
L
≥ V
Prog
/
Prog
.
Table 3-4 summarizes the effect of the Vadj adjustment. The first three columns reflect the sta-
tus of the unit before the Vadj command is issued. The fourth column shows the message on
the front panel display after the Vadj key is pressed and the fifth column shows how the adjust-
ment will affect the status of the power supply. Refer to PAR.s 3.1.1 and 3.1.2 for more details
regarding commanded and actual mode of operation (either voltage or current).
TABLE 3-3. USING VADJ AND KEYPAD ENTRIES TO SET
OUTPUT VOLTAGE/VOLTAGE LIMIT — MODELS M, MG
POWER SUPPLY STATUS BEFORE Vadj PRESSED EFFECT AFTER Vadj PRESSED
COMMANDED
MODE
OUTPUT
ENABLED/
DISABLED
ACTUAL MODE ***
(DICTATED BY
LOAD)
DISPLAY
INDICATION
NUMERIC VALUE
SET BY KEYPAD
ADJUSTS:
VOLTAGE DISABLED VOLTAGE***** CONST VOLT = Programmed output voltage
VOLTAGE ENABLED VOLTAGE CONST VOLT = Actual output voltage
VOLTAGE ENABLED CURRENT**** CONST VOLT = Actual Voltage limit **
CURRENT * DISABLED VOLTAGE***** VOLT LIMIT = Programmed voltage limit
CURRENT * ENABLED CURRENT VOLT LIMIT = Actual Voltage limit
CURRENT * ENABLED VOLTAGE**** VOLT LIMIT = Actual output voltage **
* If the unit was programmed to Current mode remotely before being set to Local Mode, the unit will stay in com-
manded current mode until a Voltage Mode command is received.
** “Overload” error message placed in error buffer (for use when operating in Remote mode).
*** Actual mode is indicated by the VOLTAGE MODE and CURRENT MODE status LED’s.
**** Condition where load forces power supply mode.
***** Forced internally by the power supply.