Overview - ABB R-MAG Series Instructions Manual

38-929M-15A 10/15/02 1:11 PM Page 33

1.0 OVERVIEW

The ED2.0 electronic control board is comprised of a Power Supply Recharge Unit, Control
Unit, and FET Switching circuit which connects the Storage Unit Capacitors to the Magnetic
Actuator coils.
The power supply recharge circuitry adapts whatever input voltage, within the specified range
(Section 2.0), is supplied to maintain an 80 V charge voltage across the capacitors. The
Control Unit monitors binary inputs and outputs, hardware and software configurations,
position sensors, capacitor charge, and switches the FET circuit to connect the capacitor
voltage to the Magnetic Actuator coils following an open or close command.
The Capacitor Storage Unit consists of two 0.1 microfarad Aluminum Electrolytic capacitors
connected in parallel to provide a total capacitance of 0.2 microfarads. The energy stored is
approximately 640 Joules. When called to energize the Magnetic Actuator coils, the
capacitors will deliver a peak current of approximately 35 A and a pulse width of 45
milliseconds for opening operations and 60 milliseconds for closing operations.
The ED2.0 board also provides access, through KM1003 for external charging and
discharging of the Storage Unit capacitors. A 10 kOhm capacitor discharge resistor is
mounted on the circuit board. Discharging is done by jumpering KM1003 pins 5 and 6. The
time constant is 33 minutes. An external resistor can be used for quicker discharging, but the
discharge current should be restricted to 10 A maximum. An external resistor can be used for
quicker discharging, but the discharge current should be restricted to 10 A maximum. This
means that no lower than 10 ohms external resistance should be used to perform capacitor
discharging. In this case an external 10 ohm, 25 watt resistor can be connected to KM1003
Pins 5 and 6. Approximately 40 seconds is needed to discharge the capacitors using the 10
ohm external resistor.
The MTTF for the ED2.0 Control Board (Mean Time To Failure) is 30 years.
The ED2.0, with external circuitry, system Block Diagram is given in Illustration 1 below.
ILLUSTRATION 1 – ELECTRICAL SYSTEM BLOCK DIAGRAM
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