YASKAWA L1000A Technical Manual page 151

Light Load Direction Search Function
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Light Load Direction Search can be used to automatically perform Rescue Operation in the direction with the lower load.
It can help to minimize the amount of power required by the backup power supply required for Rescue Operation. Light
Load Direction Search can be set so that it is automatically performed when Rescue Operation is started. To enable Light
Load Direction Search set parameter S4-01 = 1.
When Light Load Direction Search is enabled the drive first runs in the up and then in the down direction, each for the
time set to S4-03. It then compares the load condition of both operations and travels to the next floor using the lighter load
condition direction. The speed reference used for Light Load Direction Search can be set in parameter S4-04.
• When the lightest load direction is up, the drive stops after Light Load Direction Search and then accelerates upwards to
the Rescue Operation speed set in parameter S4-15. The output terminals set for "Light Load Direction" (H2- = 54)
and "Light Load Direction detection status" (H2- = 55) will close.
Figure 4.40
Light Load Direction Search status
• When the lightest direction is down, then after Light Load Direction Detection is finished the drive immediately
accelerates to the Rescue Operation speed set in S4-15 without stopping. An output terminal set for "Light load
direction" (H2- = 54) will stay open, and an output terminal set for "Light Load Direction detection status"
(H2- = 55) will close.
Figure 4.41
Light Load Direction Search status
YASKAWA ELECTRIC SIEP C710616 38F YASKAWA AC Drive - L1000A Technical Manual
H1- = 55
Off (open)
(Rescue Operation)
Off (open)
Up/Down command
Up command (internal)
Down command (internal)
H2- = 55
H2- = 54
Light load direction
Figure 4.45 Light Load Direction Detection (Up)
H1- = 55
Off (open)
(Rescue Operation)
Off (open)
Up/Down command
Up command (internal)
Down command (internal)
H2- = 55
H2- = 54
Light load direction
Figure 4.46 Light Load Direction Detection (Down)
4.6 Setup Procedure for Elevator Applications
On (closed)
On (closed)
Speed agree torque calculations
Up
Down
Off (open)
Off (open)
On (closed)
On (closed)
Speed agree torque calculations
Up
Down
Off (open)
Off (open)
Up
Elevator moves in the
direction of the light load
On (closed)
On (closed)
Elevator moves in the
direction of the light load
On (closed)
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