Alpha Technologies Spectra Series - Manual (Page 33)

Preliminary Operating Instructions 33 of 62 AIP SERVICE NUMBER 1-800-863-3364
Enter the measured or calculated value as the Offset set point. (Factory setting of 0.00V with a
maximum of 2.50V)
Temp Comp
Sets the type of temperature compensation that adjusts the output voltage of the charger
depending on the temperature. The choices are:
• “Dis” for disabled or no temperature compensation
• “In” for internal temperature compensation based on the temperature sensor on the SCR
Driver Board
• “Ex” for external or remote temperature compensation based on the Optional Remote
Temperature Sensor. The “Ex” in this submenu only shows, if the Remote Temperature
Sensor is plugged into JP5 on the SCR Driver board.
Temperature compensation is based on a reference temperature of 77°F (25°C). The
Temperature compensation factor is - 2.5 mV (millivolts) per Cell per Degree F (- 4.5 mV per cell
per Degree C). The compensation factor is NEGATIVE because of the inverse relationship
between the temperature and the voltage (i.e. as the temperature increases the voltage should
decrease).
See the InTemp or ExTemp menu section for the temperature that the charger uses to determine
the float or equalize voltage after temperature compensation. This value is used for the
calculation.
The equivalent equation for the compensated voltage is:
V – ((- 0.0025 * k) * (77
°F - t)) = Vcomp for Fahrenheit
V – ((- 0.0045 * k) * (25
°C - t)) = Vcomp for Celsius
• V - is the nominal Float or Equalize voltage of the battery at 77°F (25°C)
• t - is the temperature in °F or °C according to the temperature sensor being used for
compensation
• k – is the number of cells.
• Vcomp - will be the new float or equalize voltage for the charger
Example 1:
If a 60-cell battery is charging with a Float voltage of 2.25 volts per cell or 135 volts, and the
temperature increases to 95
°F, then the output float voltage decreases to 132.3 volts.
( 2.25 * 60) – ((- 0.0025 * 60) * (77
°F - 95°F)) = 132.3 volts
Example 2:
If a 24-cell battery is charging with an Equalize voltage of 2.32 volts per cell or 55.68 volts, and
the temperature decreases to 20
°C, then the output equalize voltage increases to 56.22 volts.
( 2.32 * 24) – ((- 0.0045 * 24) * (25
°C - 20°C)) = 56.22 volts
The Battery Charger will switch back to “Dis” or no temperature compensation if the temperature
sensor detects 32 °F (0°C) or has been disconnected.
11.3.4 ALARM SETTINGS
The Alarm Settings menu allows the user to have the following fault conditions armed (enabled)
or disarmed (disabled) and allow the alarm to be turned on or not because of that fault condition.
It also allows the user to change some of the factory default values to user-desired values.
Disarming the fault will mask it out of the Fault menu and will cause the summary alarm to not
turn on because of it. If the optional ALARM I/O Relay board is equipped the fault will not be
displayed on it either. All faults are factory set to be armed or enabled.