Vertiv Liebert STS2/PDU - Remote Source Selection Wiring

Vertiv™ | Liebert
®
STS2
™
100-1000A, 50/60Hz User Manual | Rev. 12 | 11/2017 15
6.8 Remote Source Selection Wiring
An optional Remote Source Selection board may be installed in your Liebert STS2. This board is installed in the
same bay as the communications options. See Figures 19 and 20 for the location of these options. See
Figure 21 for information on the control wiring for the Remote Source Selection option.
The Remote Source Selection allows you to choose the preferred input source from a remote location. Terminal
connections allow the customer to remotely select a source to be the preferred source in the same process as
the local source transfer selection.
The unit’s preferred source selection and Remote Source Selection are active at the same time, with the Liebert
STS2 following the last request for a preferred source change, regardless of whether it was from the local or
Remote Source Selection controls.
A six pin terminal block provides the Remote Source Selection connections. Two pairs of wires are used from the
switch to trigger the source selection. You can select the type of switch used for this remote control. Connections
are made to four of the connections, using Form A dry contacts. The contacts are numbered left to right:
See 10.3 - Enabling Remote Source Selection for instructions on enabling the Remote Source Selection option.
6.9 Key Lockout Switch
The key lockout switch activates a software lockout of the touchscreen display to prevent manual transfers and
configuration changes. When locked out, the touchscreen becomes a read only display. A key is needed to do
manual transfers or change settings.
The alarm silence button is not disabled when in the lockout position.
The switch is located behind the front door but can be operated without opening the front door. See Figures 7
to 9 for the key lockout location on each unit.
See section 13.2.1 - Security for key lockout switch operation with the LCD touchscreen. See 14.1.4 - Key
Lockout Switch for key lockout switch operation with the LED display.
6.10 Redundant Output Breaker
An output plug-in, non-automatic circuit breaker is provided which allows redundancy in the output power path.
The breaker is connected in parallel with the output plug-in non-automatic circuit breaker.
6.11 Transfer Inhibit
Transfer Inhibit prevents the Liebert STS2 from transferring under certain conditions. When a customer-supplied
closed dry contact is provided, the Liebert STS2 will not transfer and remain on its present source even if the
source is no longer supplying power.
This option requires an Input Contact Isolator board (see 6.4 - Input Contact Isolator Board).
Table 4 Remote source selection terminal block
Contact
Connection
1Source 1
2 Isolated ground
3Source 2
4 Isolated Ground
5 DO NOT USE
6 DO NOT USE