Using The Ups With A Generator; The Automatic Transfer Switch (Ats); Figure 92: Timing Variables When Using A Generator And An Ats - Gamatronic B60US-IB Installation Manual

8. Using the UPS with a Generator

At many sites a generator is used as a reserve source for feeding the UPS during mains power
failure.
8.1.

The Automatic Transfer Switch (ATS)

In such cases, the switching between the two sources (the mains and the generator) is performed
by an Automatic Transfer Switch (ATS). Because these two sources are not usually synchronized,
switching between them requires an interval of at least 10 seconds.
Figure 75 illustrates the timing factors involved when using an ATS. For proper functioning of the
UPS, the values used for T3 and T4 must be greater than 10 seconds.
Figure 75: Timing variables when using a generator and an ATS
UPS for 208 Vac Grid, Installation Guide, doc. rel. 3.0 94