Instructions

67
5.5 Parallel Operation
5.5.1 Introduction
Up to six units of the same Voltage and Current rating can be connected in parallel to provide up
to six times the output current capability. One of the units operates as a master and the remaining
units are slaves. The slave units are analog programmed by the master unit. In remote digital
operation, only the master unit can be programmed by the computer while the slave units may
be connected to the computer for voltage, current and status readback only.
The Master and Slave modes are stored in the power supply EEPROM when the AC power is turned
off. The system will return to the Master/Slave mode upon re-application of AC power.
There are two methods to configure multiple supplies for parallel operation (basic and advanced).
Refer to Section 5.5.2 and to Section 5.5.3 for detailed explanation. Parallel modes are selected
via Front Panel menu. Refer to table 5-2.
Subsystem Level Function Level Parameter Level
Description Display Function Display Description Display
Parallel Operating Mode
r
Host /Basic Slave /
Advanced Slave
HOst
Single power supply
H1
Master
H2
.. H
Se
Slave (Basic)
S
Slave (Advanced)
SAD
Table 5-2. Parallel subsystem menu
5.5.2 Basic Parallel Operation
In this method, setting the units as Master and Slaves is made by the rear panel J1 connections
and setup via Front Panel. Each unit displays its own output current and voltage. To program the
load current, the Master unit should be programmed to the total load current divided by the
number of units in the system. The master and slave units operate in a Daisy-Chain connection
configuration. For further details about Daisy-chain connection refer to section 5.6. Refer to the
following procedure to configure multiple supplies for basic parallel operation.
5.5.2.1 Master Unit Set Up
During operation, the master unit operates in CV mode, regulating the load voltage at the
programmed output voltage. Connect the sensing circuit to local or remote sensing as shown in
Fig.5-4 or Fig.5-5. Front Panel Main Menu Parallel mode is ”H1” as default.
1. Press MENU button.
2. Rotate Voltage encoder until ”r” appears on Voltage display, then press Voltage encoder.
3. Rotate Current encoder until ”H1 ” appears.
4.
Press Current encoder to select ”H1 ”, the display blinks once and returns to previous menu level.
5. Set the master unit output voltage to the desired voltage. Program the current limit to the
desired load current limit, divided by the number of parallel units.
6. If there is more than one Slave unit connected to the Master, then set the PS_OK signal delay
of the Master to 200msec. Refer to section 5.7.4 Power Supply OK Signal.
Display Operating Mode
H1
Single unit (default)
H2
Master unit with 1 Slave unit
H3
Master unit with 2 Slave units
H4
Master unit with 3 Slave units
H5
Master unit with 4 Slave units
H
Master unit with 5 Slave units
S
Slave unit (Basic mode)
SAd
Slave unit (Advanced mode)
Table 5-2.1: Operation Setting Mode