Power supply ICOS-PS 3160 series
Installation, use and maintenance manual - EN
Ver. 1.05
47
6.2 Capacitors charging
For the stabilization of the rectified line voltage, the power supply unit contains high-capacitance electrolytic
capacitors, initially discharged. The initial charging must be adequately controlled, in order to prevent the
mains from absorbing a large peak of current (inrush current), which might cause the following
inconveniences:
• high stress on the electronic components (diode bridge, capacitors);
• intervention of upstream protection devices;
• voltage drops which might affect other devices.
This phase, called “charging”, is started by the power supply unit when it receives a digital signal on the
RESET input, while the power supply is ON.
The charging phase is also repeated after the first start, whenever a diagnostic alarm disables the power
supply unit output; also in this case, the charging phase is started after a signal on the RESET input.
While waiting for the RESET signal and during the charging phase, the PWG LED is flashing.
When the charging phase is completed, the power supply unit is ready and the PWG LED will be ON and
steady; the PWG digital output will be activated.
Here is a summary table:
Before the charging phase is completed, it is not possible to apply any load to the power
supply unit output, otherwise the power supply unit would be damaged.
Condition
PWG LED
PWG output
Meaning
Start or alarm
Lamp
0
Waiting for the RESET signal
RESET 0 → 1
Lamp
0
Charging phase
Full charge
On
1
Power supply unit ready
