HYDAC EDS 601 - Manual (Page 15)

Appendix C: Application example
Accumulator charging circuit:
When the system pressure is reached, relay 1 switches the pump into the
bypass. If the pressure falls by the value of the switching hysteresis, the pump
begins to feed to the system again. The switching direction of relay 1 was set to
"OFF“ and the N/O contact was used as the switching contact. This guarantees
that the pump is not operating if the EDS 601 is switched off.
Relay 2 switches a warning light which lights up when the system pressure is
too low. As it also needs to light up if the EDS 601 is switched off, the switching
direction of relay 2 was set to "ON“ and the N/C contact was used. To bridge
short-term pressure surges, the switch-back delay was programmed to
2 seconds.
For documentation purposes, the analogue output is also connected to a central
data acquisition unit (DAU).
8.
warning light
pressure- min.
UB
0V
Rel 2
Rel 1
1
2
3
4
5
6
to DAU
0V
20 .. 36 V 1
2
3
EDS 601
E