HP 750 - Manual (Page 39)

4-4 Preventive Maintenance C4705-90000
Scheduled Maintenance
In some segments of the plotter market, the customer tends to print more than the maximum
number plots that the throughput allows, exceeding by far the limit of the design. When this
happens the customer runs into print quality problems and continuous plotter failures.
The purpose of scheduled preventive maintenance is to avoid these failures Ć ensuring a good
performance during all the product life.
Level of Plotter Usage
These are the usage limits of the plotter:
D The service station and spittoons: Limited by the number of spits, wipes and primes
performed which are directly proportional to the number of plots.
D The YĆaxis: The wear of the motor depends on the number of carriage cycles. The levels
of friction can increase due to dust and inkaccumulation on the slider rods.
Given these constraints, preventive maintenance is required when the plotter usage exceeds
the following thresholds:
Number of plots: 20, 000
Number of carriage cycles: 4,500,000
Customers with a normal plotter usage will not require any maintenance.
During the plotter life (5 years, 220 working days per year) normal plotter use means less
than (on average):
20 pages per day in CAD
or
12 pages per day in LFP
Implementation
Two of the EEROM counters are assigned to counting the number of plots and the number of
carriage cycles respectively.
When the plotter exceeds the limits quoted above, the front panel displays the following
message:
Maintenance Advised"
The configuration plot also conveys the usage information, and it is accessible by the user.
Usage Information
Number of plots
Number of carriage cycles