I have the service manual but have not been able to find out or locate anything that will tell me what the rated monthly duty cycle of this printer is.
I am trying to determine if a PRO 3880 printer a local seller in my area has been used excessively or not. I do know when it was originally put into service.
I do not own an Epson 3880, but do have a Service Manual (Revision B, which appears to mean it is the 3880 update to the 3800 manual). There of course is nothing about "duty cycle", as that is relatively meaningless for a printer. But if you look at page 13 under "Product Description Basic Specifications" and "Section 1.2.4 Reliability/Durability" they specify 12,000 pages, 1.6 million carriage cycles, and list the MTBF as 20,000 hours of power on time. That last might be hard to interpret, but if the machine is actually in use 8 hours per day that would equate to more than 6 years.
On page 255, under "Maintenance Overview" in "Section 6.1.1 Product LIfe Information" it lists 5 years of service, 12,000 pages, 1.6 million carriage cycles and 28 trillion shots per nozzle. It also says certain assemblies have resetable counters and should be replaced at specific counts. The air pump assembly is good for 400,000 revolutions, the waste ink cartridge holder for 1,200 removals, the ink tubes for 4 million cycles and the absorbers for borderless prints for 10,000 pages.
Some of the above would be information available from normal user info and some probably requires a maintenance mode to see the counters. But overall one can probably get some idea (with a few questions to the original owner about what size and type of prints were typically being done) of how long it can be expected to last. Note that the "pages" specified are A2 size on plain paper in "fine" mode, so the actual print count can be expected to go higher for most work loads.
In a business environment, working 250 days a year for 7 continuous hours a day it would take nearly 2 years to reach the limit of 12,000 A2 prints. Hence that 5 years service life for the printer appears to mean with something roughly about at a 40% duty cycle during normal business hours.