User`s manual

CHAPTER 5.0 Functional Overview 5-4
CDS7324 (FORMERLY LSF-0819)
Rev. A INSTALLATION & USER’S MANUAL
5.3.4 Low Voltage Control Power Supply
Control power for the logic circuits is generated by a DC/DC converter, which provides control-circuitry power that
is isolated from the mains input. This control voltage also powers the cooling fans on size A-D. Size E Drives
require separately supplied 24Vdc to power the cooling fans. The DC/DC can generate control power from two
sources
1. D.C. Bus if it is greater than 120Vd.c. (Not available on the DS2110 µA size drives)
2. 24Vd.c. external supply which is provided by the user specifically for control-backup power
These two sources are diode ‘ORed’ together to produce the internal 24V logic backup supply.
The state of the internal control electronics logic supplies are available to the user to monitor. If these supplies are
out of tolerance the drive will report a fault and react accordingly. The parameters associated with viewing the
internal logic supplies are given below.
Parameter Name Field Number Description
supply_+24V
1441 Internal 24V Logic Supply
supply_+3V3
1421 3.3V Logic Supply
supply_-15V
1426 -15V Logic Supply
supply_+15V
1431 +15V Logic Supply
supply_+2.5V_ref
1436 2.5V Reference Level
encoder_supply
1446 Encoder Supply
Table 5.2 Logic Voltage Supply Monitoring Parameters
If the internal 24V logic supply voltage falls below 20V, the drive will disable and enter a fault status (F9). The
drive will automatically perform a power down save which saves certain data to memory such as elapsed time.
This save does not however save all parameters to non-volatile memory. Any unsaved parameters will be lost if
the internal 24V logic backup is lost.