Operation; Notices On The Application Of Control Blocks At Low Temperatures - Bosch rexroth M1-16 Series Instruction Manual

38/54 Control blocks for mobile applications | Operation
Boundary conditions
General instructions
Bosch Rexroth AG, RE 64025-B/2021-08-12

9 Operation

This product is a component which requires no settings or changes during
operation. For this reason, this chapter of the manual does not contain any
information on adjustment options. Use the product only within the power range
specified in the technical data. The machine manufacturer is responsible for the
proper project planning of the hydraulic system and its control.
▶ Avoid temperature shocks. A temperature difference of more than 20 °C
between the control block and the hydraulic fluid must not occur. Otherwise,
there is a risk of a jammed spool. At temperatures below 0°C, the control block
must be run until it is warm.
9�1 Notices on the application of control blocks at low
temperatures
• Minimum ambient temperature:
• Hydraulic fluid temperature
– Warm-up phase with low loading
– Operation with low loading
– Operation with loading
• For applications below an ambient temperature of –20 °C, non-standard seals are
used. Different application limits are specified in the control block's Technical
Customer Documents (TKU).
• Avoid moisture in the area surrounding the control blocks, since possible
moisture on the moving seals may freeze the seal to the control spool when at a
standstill. When moving the control spool, it is not possible to rule out the seal
ring being destroyed.
• The limit viscosities specified in the data sheets for the control blocks must be
complied with by selecting a suitable hydraulic fluid across the entire operating
time both in winter and in summer with warmer temperatures.
– The values below apply to limiting conditions:
ν
= 2000 mm²/s
max
(Momentarily on cold starting, ϑ
ν
= 10 mm²/s
min
(Momentarily at max. permissible temperature of ϑ
Note that the max. hydraulic fluid temperature of 80 °C (100 °C with FKM) must
not be exceeded, not even locally, e.g. at the pressure reducing valve.
• When installing new components in a cold machine, they must first be filled at
higher temperatures so that sufficient lubrication is assured in all areas.
–40 °C
as of –40 °C
as of –20 °C
as of 0 °C
= –40 °C)
min
= 80 °C/100 °C)
max