ATS Model

The ATS model in the Dynamic Stability engine simulates one-way automatic transfer from Normal (left) to Emergency (right) on an ATS equipment item. The settings for this device are found under the Stability tab in the ATS Data dialog box, and are:

Parameters

Parameter

Units

Description

Trip Voltage

Percent

Normal bus voltage at which ATS picks up.

Del on Start

Seconds

Time in under-voltage condition before transfer.

Req Voltage

Percent

Voltage required on Emergency bus for transfer.

Neutral Del

Seconds

Neutral delay time.

Mech Del

Seconds

Mechanical delay time.

In addition:

  • After the voltage has dropped below the Trip Voltage for a time of Del on Start, and the Emergency bus voltage is greater than Req Voltage, a transfer is commenced, and is delayed for Neutral Del + Mech Del seconds. After the delay is satisfied, the ATS is transferred to the Emergency bus.
  • If the voltage on the Emergency bus is not above the Req Voltage, then no transfer is made. If the Emergency bus voltage rises above Req Voltage, and a transfer is in process, then the ATS will transfer. Thus, the Req Voltage is the last check for a transfer. If all conditions are satisfied for a transfer, the ATS will wait for the Emergency bus voltage to rise above Req Voltage, and then instantaneously transfer.
  • If the Normal bus voltage rises above Trip Voltage before Del on Start is satisfied, the ATS performs an instantaneous reset, and remains on the Normal bus.
  • When the ATS’ Switch Type is a Primary Selector Switch, then all ATS functionality is disabled.
  • You must own EasyPower Power Protector to have the contactor model feature in the Dynamic Stability engine.

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