3 - 4
Introduction to Sigma LT Digital Toggle Switches
The Sigma LT digital toggles are fitted as standard to all Sigma LT load banks. The control
panel is for local control only and instrumentation is displayed on the seven segment
digital display.
Figure 3-2
Sigma LT digital toggle control panel
MODE.
The mode button has three functions.
1. Press mode to cycle through the different instrumentation displays: 3 phase
Voltage and Currents or Voltage, Frequency and Power. The LED will illuminate of
the instrumentation selected. (Please note cycling through instrumentation is only
available in 3 phase mode).
2. Press and hold mode for 4 seconds to select single phase (1ph A-C |
Conn 1ph
a-C
or 1ph AB-C |
Conn 1ph a-bC
) and three phase (3ph ABC |
Conn 3ph abC
)
connections. Leave for 5 seconds to select. Ensure the connection mode selected
matches the power connection wiring.
3. Press mode to acknowledge an error if displayed.
LOAD SELECT.
The load select buttons have two functions.
1. Press and hold at power up to set the load limit. See figure 3-3. Please note the load
limit selected will be saved.
METERING
MASTER
LOAD
5 kW
5 kW
10 kW
10 kW
25 kW
50 kW
50 kW
50 kW
REMOTE
LOCAL
ON
MODE
!
V/Hz/kW
V x 3
A x 3
LOAD
SELECT
R
ASCO
3000 Series
480 0 59 9 70 0
Mode
Load Select
Metering Display
Error Warning Lamp
Master Load
Local/Remote
Control Selection
Warning! The Fan and
Controls Supply Isolator
does not isolate the
main power wiring from
the Supply-on-Test.
Some of the circuits
within the load bank
will remain live when
the switch is in the off
position.
Digital toggle switch control operation
3 - 5
Figure 3-3
Load limit buttons with load limit amounts.
2. Press any combination of the load select switches to choose the required load in kW.
LED’s will illuminate of those selected. If 30kW is required, press 5kW, 5kW, 10kW and
10kW. Then press master load on. Alternatively if master load is already on there will
be a one second delay then load will be applied automatically. The one second delay
allows a synchronous load change.
MASTER LOAD.
Master load applies any load selected when turned on and rejects all load
when turned off. The master load LED will illuminate when on and extinguish when off.
LOCAL/REMOTE CONTROL SELECTION.
Switch between local and remote control.
Selected control will be indicated by the illuminated LED. Remote control mode is only
available when a Sigma LT hand-held is connected. Control will automatically switch to the
hand-held when connected.
ERROR WARNING LAMPS.
LED lamp will illuminate if an error occurs, the error type will
appear on the metering display. Press mode to acknowledge the error.
Sigma LT Digital Toggle Switches - Quick Start
1.
Connect the load bank to a power source and the supply on test (see chapter 2).
2.
Turn the fan and controls supply isolator on.
3.
Turn the master load switch on. The master load LED will illuminate. If load is applied,
press master load to immediately reject all load on test.
4.
Press any combination of the load select switches to choose the required load in kW.
For example, If 30kW is required, press 5kW, 5kW, 10kW and 10kW. Then press master
load on. Alternatively if master load is already on there will be a 1 second delay then
load will be applied automatically.
5.
Repeat step 4 to change the load i.e. if the load required is now 20kW press one of the
10kW switches to deselect and after a one second delay 20kW of load is applied. The
one second delay provides a synchronous load change.
6.
Press mode to cycle through the instrumentation types.
7.
Press master load to reject all load on test.
Chapter Three
METERING
MASTER
LOAD
5 kW
5 kW
10 kW
10 kW
25 kW
50 kW
50 kW
50 kW
REMOTE
LOCALO
N
MODE
!
V/Hz/kW
V x 3
A x 3
LOAD
SELECT
R
ASCO
3000 Series
25%
50%
75%
100%
Model
Load Limit
(kW)
Version
