LINK Systems System 1100 Tonnage Monitor - Manual (Page 87)

8-1
Most machines that use force in production processes are designed
for distributed central loads at rated tonnage and lesser non-
central (eccentric) loads. However, some forging presses and other
machines are designed to permit operation at full tonnage with
either central loads or, within specified limits of offset from
center, non-central loads.
The procedures in Section 6 "Calibration" of this manual are
written for machines designed for rated tonnage only with
distributed central loads. Since a central load will be
distributed equally to each side of a "C" frame machine or to each
column of a straight side machine, a two channel tonnage monitor
expects 1/2 of rated machine tonnage to appear on each channel when
the machine is operated at rated capacity. A four channel tonnage
expects 1/4 of rated machine tonnage to appear on each channel when
the machine is operated at rated capacity. The machine rating
alarms for any channel are tripped any time, the tonnage of the
channel exceeds 125% of the tonnage expected at full load, as
explained in the following examples.
Example 1. A 100 ton OBI press is equipped with a two channel
System 1100 Tonnage Monitor, with strain links mounted on each side
frame member. A central load at rated tonnage will register 50
tons on channel 1 and 50 tons on channel 2 when a machine rating of
100 tons is programmed into the unit and the calibration
instructions of this manual are followed. Programming the machine
rating at 100 tons automatically sets the machine rating alarms at
62.5 tons (125% of 50 tons) on both channel 1 and 2. No tooling
can be run in the machine that produces more than 62.5 tons on
either side of the frame.
Example 2. A 100 ton straight side press is equipped with a four
channel System 1100 Tonnage Monitor. A central load of 100 tons
will register 25 tons on each of the four channels. When a machine
rating of 100 tons is programmed into the unit, and the calibration
instructions of this manual are followed, the System 1100
automatically sets the machine rating alarms at 31.25 tons (125% of
25 tons) for each channel. No tooling can be run in the machine
that produces more than 31.25 tons on any column.
The machine rating number that must be programmed into the System
1100 is simply a scale factor. For machines that are designed to
operate at full rated tonnage with an off center load, a machine
rating alarm fixed at 125% of expected channel tonnage at full load
Section 8. Unbalanced Loads and Scale Factor