Rotating Pumps By Service Ratio - Siemens HydroRanger 200 HMI Operating Instructions Manual

Operating
7.9 Pump control
7.9.4.2

Rotating pumps by service ratio

Prerequisite: Set pump relays to a service ratio value [(Relay Function (2.8.1.4.) (Page 195)
= Service Ratio Duty Assist or Service Ratio Duty Backup].
Parameter
Service Ratio (2.8.1.12.)
(Page 200)
Service Ratio (2.8.1.12.)
(Page 200)
Service Ratio (2.8.1.12.)
(Page 200)
Note
• The device will not sacrifice other pumping strategies to ensure that the ratio is held true.
• If the pump relays are set to the same value, then the ratio equals 1:1 and all pumps are
used equally (preset).
When more than one pump is assigned a pump service ratio value (in any time units) and a
pump start is required [ON setpoint (2.8.1.5.) (Page 197)], the pump with the fewest running
hours (with respect to the assigned ratio values) starts. Conversely, when a pump stop is
required [OFF setpoint (2.8.1.6.) (Page 197)], the pump with the most running hours (as
compared to the assigned ratio values) stops.
126
Index Value
1 1
2 2
3 1
Operating Instructions, 06/2018, A5E36281317-AC
Description
These values will start Pump 2 fifty
percent of the time, and Pumps 1
and 3 each, twenty-five percent of
the time.
HydroRanger 200 HMI