ROBWAY RCI-4100 Operation And Installation Download

Page: 118 / 187

DATA LOGGING DESCRIPTION

MAN-1111 Rev H

Page 118

Type 2 Log- Out of Load Chart / Error conditions

A log cycle is started when:

•

SWL drops to 0, implying SWL % is unknown but definitely greater than 110%. In this case the SWL is

nominally set to 110% and appears as ">110%" in the logger print out

During a log cycle:

•

The load is monitored and the peak load seen is continually updated (in log 1)

•

The radius is monitored and the max. Radius seen is continually updated (in log 2)

A log cycle is completed when:

•

SWL becomes > 0 (log 1 AND log 2 are stored and condition for starting a type 1 log is checked)

Hence, if a load is lifted within the load chart a single log is performed.  If the boom is positioned outside of
the load chart, any log cycle in progress is stored and a new cycle begins.  During this overload cycle two
individual logs will be performed.  One log will record the maximum load reading which is observed and the
other will record the maximum radius which is observed.  It is necessary to perform two logs because it is
impossible to know which is a more unsafe condition, a longer radius or a shorter radius but higher load on
the hook.

Stable loads are not monitored during out-of-chart/error logging cycles.

Logging on Multiple Winch Cranes

As previously stated, each winch that is being monitored will have its own set of lift counters which will
automatically increment every time a load is lifted that generates a SWL percentage exceeding the Function
Code value set for the "Low Load Lift Counter."

Actual logging of the load will occur only when the lift causes a SWL percentage which is higher than the
"Logging Percentage" set in Function codes.  It is possible to log a lift on the Auxiliary winch while the main
winch is selected on the display.

As a further precaution, on twin winch systems, SUM winch logging can also occur.  A log which refers to the
M-SUM or A-SUM winch as the affected winch is implying that the combination of main + auxiliary loads
would have exceeded the "Logging Percentage" value when referenced to what the boom can lift.  This log is
recorded in the instance when the main and auxiliary loads separately do not exceed the logging threshold
(rather the individual SWL percentages for each winch would cause the winch counters to increment) but
when considered together, they cause a SWL percentage which exceeds the "Logging Percentage" of what
the boom is capable of lifting.

In this special instance, two logs will be stored to the data logger records in addition to the normal
incrementing of the separate winches lift counters.  These special logs are easily identified in the log table as
they will identify M-SUM or A-SUM as the affected winch.  The first of the two entries (M-SUM) relates
information about the main winch condition when the (approach to) over load occurred and the second (A-
SUM) records details the auxiliary winch condition.

Example Load Lift

Suppose a driver lifts a load and luffs out.  If we assume the SWL % generated at the edge of the load chart
is sufficient to cause a log to record then as soon as the driver exceeds the maximum radius on the chart,
the active log cycle completes and is written to the logger prior to beginning an "out-of-chart" log cycle.

The out-of-chart cycle continues until the driver luffs the crane back into a safe condition.  As soon as the
safe condition is achieved, the out-of-chart logs (one for max. load and one for max. radius) will be stored to
the logger.

Because the crane is now back in a safe condition, a new logging cycle begins.  When the driver finally puts
this load down (assuming he does not luff off the chart again) the normal log cycle completes and another
log is written to the logger.