Fairford Electronics QFE Series, Руководство пользователя

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page 5-17
Programming
QFE
FD8420 issue02_F
Firing Mode 4
, for static loads with the star point connected to the neutral, and
the soft start unit using a closed loop control method (QFE+ only);
Firing Mode 5
, for static loads with the star point connected to the neutral, and
the soft start unit using an open loop control method.
This parameter is set to mode zero (0) by default.
Stop Smoothing
- This parameter stores a value which is used by a
software filter to smooth any irregularities during a soft stop, caused by an unstable load.
This parameter is used in conjunction with
Low Volts Stop
(see above) and also
Stop
Pedestal
(see section 5.3.3 ).
Low Volts Stop
must be turned
On
and
Stop Pedestal
set to 40% or less, for
Stop Smoothing
to have any effect. The maximum numerical
value that
Stop Smoothing
can be set to is fifteen (15), which gives the minimum amount
of soft stop smoothing. This parameter is set to five (5) by default.
Cooling
- This menu item turns
On
and
Off
the
Cooling
function.
Once this menu item has been turned
On
and the unit has been started and subsequently
stopped, the
Cooling
function inhibits the start command ( not allowing the unit to start ),
until the time held in
Cooling Time
has elapsed ( measured from the last stop signal).
During this period the unit displays
Stopped. Cooling
. This menu item is mainly for use
in commissioning soft start units that have large thyristor stacks, it’s purpose being to avoid
damage to the thyristors during the commissioning process. For all units this menu item is
turned
On
by default.
Cooling Time
- This parameter holds the time in seconds that the soft
start unit will ignore a start signal, if
Cooling
is turned on (see above). By default, this is
set to zero (0) for units of less than 242A. For units of 242A and above the default value is
420 seconds (7 mins). This default value can be extended but should
NOT be reduced as
it will invalidate the manufacturer’s warranty.
Temp/Alt Derate
- This parameter enables the user to derate by percentage
of Unit Full Load current, where local temperature or altitude is outside of the normal operating
range (see sections
1.4 / 1.5 of Mechanical Installation). This is set to zero (0) by default.
Line Contactor
- This menu item turns
On
and
Off
the
Line Contactor
function, which selects the use by the customer of an in-line contactor in his wiring
configuration. This menu item is
On
by default. Note: the Electricity At Work regulations of
1989 infer that any solid state starter cannot be considered as being a switching off device,
and therefore an in line contactor should be used (regulation 12). However, if the decision
is made to use a breaker instead, a new mode has been introduced so that the softstart can
trip the breaker via the alarm relay when it is in the
Stopped and ready
state (see
section 5.2.3 ). This helps to eliminate the problems that arise when the breaker is closed
and a faulty softstart has short circuit devices. The breaker option is selected by turning
this menu item,
Line Contactor
,
Off
, or by enabling bit 3 of
User Flags 4
(
P121
) .
Please note that an in-line contactor MUST be used with ‘In Delta’ mode, and that the use
of an in-line contactor is always recommended.
Thermistor Trip
(QFE+) - This menu item turns
On
and
Off
the
Thermistor
Trip
function. When the customer plugs the output of his motor thermistor into the relevant
contacts on the add-on card (see the Electrical Installation Manual, sections 2.5.4 and
2.7.2 ), and this trip is activated, then the starter will trip whenever the thermistor goes ‘over-
temperature’. This set to
Off
by default.
P126 Comms Trip
- This menu item turns
On
and
Off
the Modbus protocol
Comms Trip
. When activated the soft start unit must have serial communication every five
seconds or the unit will trip. For further details see section 5.2.3 and the Modbus Manual.
This menu item is
On
by default.