Dcreg4 Operation Description - Santerno DCREG2 Series User Manual

DCREG2
15P0059B3
DCREG4
USER MANUAL
6.10.4 DCREG4 O D
PERATION ESCRIPTION
If button PE is pressed, relay RE energizes, self-maintaining.
When PE returns to its initial position, relay RA energizes as well, self-maintaining.
Its contact on terminal 24 for ENABLE closes and the converter starts delivering output voltage. Indicator
light LMA comes on to indicate that the magnet is on.
Closed contact of digital output MDO 2 keeps digital input MDI 4 active on terminal 34 for the time set in
P177; DC output voltage is set (with par. P011 and P211), which is equal to mains 3-phase voltage
increased by 15% (e.g. 460 VDC with 400 VAC).
Max. positive voltage which may be delivered by the converter with the default value of par. P230
   
(AlfaMin) is equal to V V . 1 36 cos Min (approx. +470 VDC with 400 VAC).
SUPPLY
Then, the boost function activates, which considerably reduces the current rise time.
Current will reach the magnet rated value set in C000 within a given time. Even though the max. voltage
reference is kept set for a longer time (par. P177), voltage delivered to the magnet terminal will drop
anyhow (converter in current limit).
As soon as current is other than zero, MDO 3 contact closes, thus energizing relay RI.
If energizing button PE is pressed at any moment, the duty cycle of the equipment is not affected, thanks
to contact NO of RI parallel-connected to contact NC of button PE and to contact NC of RI, which is
series-connected to contact NO of button PE.
When the time set in par. P177 is over, contact MDO 2 opens, and the reference becomes the magnet
rated voltage set in potentiometer PV, whose full-scale value is set in par. P122.
Switching from the max. voltage reference to the rated reference of the magnet, current drops, due to a
larger resistance of the electromagnet winding when this heats up. Otherwise, if boost is set for a too long
time (par.177), once the current rated value is reached, it is kept constant.
If button PDL is kept depressed for a given time, the voltage reference slowly drops following the ramp set
in parameter P034 and unloading the material in excess (partial demagnetisation).
If button PDL is longer kept pressed, the converter shuts off and output voltage drops to zero; to set again
the desired voltage, just release button PDL.
Even if the voltage reference returns to its initial value without following any preset ramp, current will rise
slowly because the boost function is inactive.
If deenergizing button PD is pressed, relay RE deenergizes, and digital inputs MDI 5 (terminal 36) and
MDI 6 (terminal 3) are activated: input voltage reference for terminal 5 is then switched to an internal
current reference equal to the max. negative value.
This occurs with the maximum negative voltage that the converter can deliver; with the default value of
   
par. P231 (AlfaMax) this is equal to V V . 1 36 cos Max (approx. -470 VDC with 400 VAC). The
SUPPLY
boost function enables, which considerably reduces current fall time.
115/200