Each power supply and the main battery backup regulator/charger, and the RAM battery backup
charger provide an alarm contact. The alarm contact opens if any of the LED indicators listed in
the previous section are not in the normal (ON) state. The alarm contact is electrically isolated from
all other circuitry so that it can be series connected by the user with alarms in other devices.
Use a hermetically sealed electromechanical relay. The alarm contacts are rated for 24 Volts ac or
dc at 0 to 65 mA non-inductive load. An alarm condition is signaled by an open contact (1000 ohms
or more); and a no alarm condition is signaled by a closed contact (10 ohms or less).
The following table provides a functional description of the activation levels for a given LED
indicator.
LED Name Functional Description
AC Power Module Indicators (per supply)
AC IN The LED turns ON when the AC input voltage is sufficient to start the unit. This is
guaranteed to occur when the input voltage has risen to 85 Vac, but it could occur
at a lower voltage, depending on output loading and unit-to-unit variations. Once
the unit starts, the LED remains ON through the entire AC input voltage range.
The LED will turn OFF at the point where the power supply shuts down. For a fully
loaded supply, this is guaranteed not to occur until the input voltage descends
below 85 Vac. This voltage can be considerably lower, if the unit is lightly loaded
and depending on unit-to-unit variations. The unit does not shut down when the
AC input range is exceeded unless there is a failure in the power supply.
Status The LED turns ON when output voltage is within the operating range. The LED
turns OFF when the DC voltage is increased to above 26.4 Vdc and the power
supply shuts down due to an over-voltage condition. (Based on manufacturer's
