Bosch Rexroth Rho 4.0 Connectivity Manual page 73

1070072365 / 04 RhoMotion
Maintenance and Replacement
Since the experience has shown that the components only draw a frac-
tion of the given buffer current and when the device is switched off (as in
the buffer case) there is only a temperature of 30 to 45 °C inside the de-
vice, a buffer current of 8 µA per component can be assumed.
Add to this the effect that the installed GOLD CUP takes over the buffe-
ring of the components for a certain time each time the device is switched
off.
Examples:
D with 2 Mbytes (4 components) = 32 µA (8 µA per component)
D with 4 Mbytes (8 components) = 64 µA (8 µA per component)
D The RTC requires approx. 5 µA of buffer current
→ To be buffered are 69 µA resp. 37 µA.
Buffer time per year:
365 days * 24 hours = 8760 hours
200 working days with 8 hours a day (a shift) = 1600 hours
→Device is switched off 7140 hours/year and must be buffered.
Capacity of the battery:
Type AA has 1,75 Ah → 1.750.000 µAh
→Whole buffer time:
→Buffer years:
. The battery should be replaced every 3 years for security reasons.
Electric Drives Bosch Rexroth AG
and Controls
1.750.000/69 µA = 25362 hours
25362/7.140 h = 3,5 years
7−3