Power Supplies

The SD83x and SD85x Power Supply Units are designed to meet all the applicable electrical safety

data stated by the EN 50178 harmonized European

Standard Publication and the additional safety and

function data required by EN 61131-2 and UL 508.

The secondary output circuitry is accepted for SELV

or PELV applications.

They are switch-mode Power Supply Units which

convert the mains voltage to 24 volts d.c. These

power supplies can be utilized for non-redundant

and redundant applications. Redundant applications

require diode voting units SS823 or SS832.

With the type SD83x series Power Supply Units,

there is no requirement for the installation of a

mains filter. They provide a soft start feature; power-on of an SD83x will not trip fuses or earth-fault

circuit breakers. The SD822Z is also G3 compliant.

Key Features

• Simple DIN-rail mounting

• Class I Equipment, (when connected to Protective Earth, (PE))

• Over-voltage Category III for connection to primary main TN network

• Protective separation of secondary circuit from primary circuit

• Accepted for SELV and PELV applications

• The output of the units is protected against over

current (current limit) and over voltage (OVP)

• SD834 can be connected in parallel to increase output power

• Both a.c. and d.c. input at SD831 and SD834

• Floating DC-OK relay contact at SD834

Voting Units

The Voting Units SS822Z, SS823 and SS833 have been

specifically designed to be employed as a control

unit within a redundant power supply configuration. The output connections from two Power Supply

Units are connected to the Voting Unit. The Voting

Unit separates the redundant Power Supply Units, supervises the voltage supplied, and generates supervision signals to be connected to the power consumer.

Green LED’s, mounted on the front panel of the voting unit, provide a visual indication that the correct

output voltage is being delivered. Simultaneously

with the green LED illuminating, a voltage free contact closes the path to the corresponding “OK connector”. Voting Unit trip levels, are factory preset.