Alpha Technologies INEX 100A STS Module and MBS+PDU - Manual (Page 15)

Argus Technologies Ltd. 019-061-C0 Rev A WC
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1.5 Voltage and Frequency Range
The STS module has two voltage inputs and one voltage output. The two inputs are Mains voltage and Inverter
voltage, and the output is System (output) voltage. STS will detect Mains voltage and Inverter voltage in order to
decide system’s supply mode when system is running. If both Mains and Inverter exist at the input, Mains has
priority to decide the operation status of system; in other words, STS will first consider Mains status to decide
system’s running voltage and frequency. Following the confirmation of voltage and frequency, the over/under
voltage and over/under frequency is set as follows:
120Vac 230Vac
Default Voltage
110V/115V/120V 208V/220V/230V/240V
Active 138Vac 276Vac
Over Volt
Recovery 134Vac 268Vac
Active 89Vac 176Vac
Under Volt
Recovery 93Vac 184Vac
Table A–Voltage default levels
System Frequency
60Hz 50Hz
Frequency High Threshold 61.5Hz 51.25Hz
Frequency High Back 61.2Hz 51Hz
Frequency Low Threshold 58.5Hz 48.75Hz
Frequency Low Back 58.8Hz 49Hz
Table B–Frequency default levels
The STS will transfer to the auxiliary source if the priority input voltage exceeds a preset value. The over/under
voltage limit can be set through controller, as shown on the following table. Users can set any value that is in the
valid range. STS won’t accept data that is out of the valid range; for example, you can set over volt point between
117~127 for 110V system, but the data that greater than 127 or less than 117 won’t be accepted. The valid range
is determined by the rated voltage sent to STS by inverter, as 110V, 115V, 120V (shown in the table).
120Vac 230Vac
Adjustable Range
110V 115V 120V 208V 220V 230V 240V
Adjustable
Range
117~127 122~132 127~138 220~240 233~252 244~264 254~276
Over Volt
Default
Value
127 132 138 240 252 264 276
Adjustable
Range
89~105 93~110 100~114 176~198 176~209 185~218 193~228
Under Volt
Default
Value
89 93 100 176 176 185 193
Table C–Inverter/System factory defaults
NOTE: If the STS has never been set for over/under voltage through the controller, then it will set the default value as
shown on Table C. Once the over/under volt points are set through the controller, the values will be saved to
EEprom, and it will remain in effect until resetting happens; except that, the next time when STS powers on, the
Mains/Inverter voltage changes from 120V system to 230V system or 230V to 120V.