10
2.4
Alarm Connections
Eight alarm relays (and 10 alarm LEDs) are included as a standard feature of the TPSD2. The included alarms are
Low DC Current, Low DC Voltage, High DC Voltage, High Voltage Shutdown, AC Failure, Negative Ground
Detection, Positive Ground Detection, and Summary alarm. Each alarm includes two sets of form ‘C’ contacts,
enabling the user to connect multiple remote annunciators. Refer to Figure 8 for alarm contact connections.
Alarm LEDs
are provided for the following alarms: AC Fail, Low DC Voltage, End of Discharge, High DC Voltage,
High Voltage Shutdown, Low DC Current, Overload/Current Limit, Positive Ground, Negative Ground, and
Summary. Refer to Figure 9 below.
If an alarm condition occurs for a default time of longer than 5 seconds, the Summary alarm relay will activate if
the corresponding alarm is included in the Summary alarm. The HVSD alarm is default set to trigger after 20
seconds. When an alarm activates, the specific indicator on the front panel will light, any connected remote
annunciators will activate, and the display will cycle through all active alarms.
All alarm contacts for the S2A-198 relay board are designed to be fail-safe. In other words, if both the AC and DC
power are removed, each alarm will be indicating the charger’s current state. To accomplish this, certain alarm
relays are de-energized on failure (such as Low DC Current), and certain alarm relays are energized on failure
(such as High DC Voltage). Refer to Table 7 for the logic of each alarm and refer to Table 8 for alarm contact
specifications.
Figure 9 – S2A-341S Display/Control Board
Figure 8 – User Connections to Alarm Contacts on S2A-198 Board
