Kohler PowerWAVE 8000DPA RI (S2) Series, Руководство пользователя, Страница: 18 / 88

2: General Description
10
TS_616_08 PW8000DPA ST (S2) User Manual 21/4/22
UPS ON MAINTENANCE BYPASS
Figure 2.7 UPS ON MAINTENANCE BYPASS
Although the maintenance bypass switch is not fitted within the UPS module, the maintenance bypass mode of operation
is shown here for completeness. A maintenance bypass switch (IA1) is fitted to the UPS cabinet switch panel and, when
closed, it provides an alternative power path for the load which completely bypass the UPS module(s). This mode is
primarily used to maintain the load supply when it is necessary to completely shutdown the UPS cabinet for repair. The
maintenance bypass line is connected to the same unprotected supply source as that used by the static switch so for
reasons of load security the UPS should only be operated in this mode when absolutely necessary.
2.3.3 UPS system operation
Summary of UPS module operating modes
UPS installations are generally categorised as being either ‘
ON-LINE
’ or ‘
OFF-LINE
’ systems; and the PW8000DPA ST
can be configured to operate in either mode. The two systems are described below.
ON-LINE UPS system
An ‘
ON-LINE
’ system provides the highest degree of load protection, especially in the event of a mains supply disturbance
or complete failure, and we always recommended its use if the critical load (e.g. computer system) will not tolerate even a
very brief supply interruption.
When the PW8000DPA ST is used as an ‘
ON-LINE
’ UPS it is configured to normally operate in the
ON-INVERTER
mode,
as shown in Figure 2.4. In the event of a UPS input mains supply failure, the UPS changes to its ON-BATTERY mode
(Figure 2.5) without affecting its output supply – i.e the UPS will continue to provide its rated output running from battery
power and the changeover to battery operation is totally transparent at the UPS output.
If the UPS input mains supply returns when the module is operating on battery power the module will automatically revert
to normal
‘ON-LINE’
operation once the returning input mains supply is validated.
If the UPS input mains supply does not return when the module is operating on battery power, it will continue to provide its
rated output until the battery discharges to a low cut-off point, at which time the UPS will attempt to switch to its ‘on
bypass’ mode; however, if the bypass input supply is unavailable the module will shut down in a controlled manner. An
audible and visual alarm will warn the operator that the battery is discharging to enable any necessary intervention actions
to be carried out to safeguard the load integrity (e.g. initiate a data backup).
It is usual, especially in larger installations, to provide the UPS with an alternative input supply from a standby generator
which starts automatically following a mains supply failure. If such a standby UPS input power source is made available it
means that the batteries discharge only until the generator comes on-line. This not only avoids the UPS from eventually
shutting down due to discharged batteries but the short battery discharge period also increases the battery life cycle.
AC/DC (PFC)
CONVERTER
DC BOOST
CONVERTER
DC/AC
INVERTER
BATT. CHARGER
STATIC
SWITCH
UPS AC
Output
UPS
Bypass
Mains
UPS
Input
Mains
BATTERY
UPS MODULE
Input
Relay
Automatic
Batt. Switch
Output
Relay
MAINTENANCE
BYPASS