User manual

Publication 1760-UM001A-EN-P
Retention 7-15
Operating Hours Counter for Maintenance Intervals
Ta sk 2
Every 1000 hours, the system or machine must have preventive maintenance
performed. Filters and transmission oil must be changed and the bearings
lubricated.
Contacts and relays used:
Function of the Pico circuit diagram:
T8 provides the clock pulse. When a time of t = 30 minutes is selected, the
counting period amounts to 2 x t = 60 min. Every hour, one pulse is counted. The
up counter C8 triggers a warning light at 1000 by means of Q4.
For the clock pulse to be correct when there is a power outage, T8 must be
retentive.
M16 prevents C8 from accidentally receiving a counter pulse when the power is
turned back on if there was a power outage during the counting period.
Both M16 and C8 must retain their actual values at power outage so that the 1000
hours of operating with interruptions in the power supply can be counted.
I1 (for example, a key-operated switch) is used to reset the counter.
Coil Function
T8 Clock pulse
M16 Block double pulse
Q4 Warning light, 1000 h reached
C8 Up counter
I1 Reset
-----------TT8
T8-M16-----CC8
-------SM16
T8--------RM16
C8---------{Q4
I1---------RC8
RT8
18:38
30.00
TRG
RES
T8
+
{
{
M:S
1000
DIR
CNT
RES
C8
+
0107
{
{