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GRAF manufactured systems used in duty standby pump station packages

GRAF Australia

Commercial pump stations guide

Duty standby pump stations

Plan redundancy, alternation and backup starts when a single pump is not enough for commercial risk.

Request a project quoteCall 1300 131 971

In short

Duty standby pump stations keep a second pump available for backup or alternating operation while sharing a wet well and control panel. Commercial pump station packages can include this redundancy when project risk, starts or authority requirements demand it. GRAF | PRESS, REUSE and CARE, plus commercial pump station packages, are being rolled out Australia-wide excluding Victoria. Project delivery, commissioning and field attendance are confirmed against location and scope.

How it works

Duty and standby pumps share the wet well. The control panel manages alternation, backup starts and alarms.
Duty standby pump stationsTwo pumps share one wet well. The duty pump runs under normal level control while the standby pump is available for backup or alternating starts.Shared wet wellLevel sensors / floatsDuty pumpStandby pumpControl panelAlternation / backupAlarms + startsRedundancy is selected from risk, starts and project specification

What to do next

  1. 01

    Define continuity risk

    Flooding, sewer surcharge, occupancy and authority expectations for backup.

  2. 02

    Confirm hydraulic duty

    Flow, TDH and whether assist start is required under peak inflow.

  3. 03

    Specify control logic

    Alternation, lag start, alarms and BMS signals with the commercial pump station package.

When redundancy is justified

Commercial buildings, basements with high consequence of flooding, sewer lift stations with limited storage, and sites with long response times often specify duty/standby rather than a single pump.

Redundancy does not replace correct storage and TDH. It reduces the impact of a pump fault or maintenance outage.

GRAF wet well configured for duty and standby pumps
Shared wet wells need space and guide arrangements for multiple pumps.

Control philosophy to confirm early

Decide whether pumps alternate on each cycle, whether the standby unit only starts on fault, and whether high-level conditions call for assist operation.

Include alarm destinations, run-hour expectations and any BMS or telemetry requirements so the panel scope matches site operations from day one.

GRAF underground commercial pumping installation
Commissioning should prove alternation and backup starts, not only single-pump run.

Compare options

Match pump count and logic to risk, not habit.

ArrangementTypical useNotes
Single pumpLow consequence / temporaryNo onboard backup
Duty / standbyMost commercial stationsAlternation or backup on fault
Duty / assistPeak inflow eventsSecond pump supports high level
Multi-pumpHigher capacity sitesConfirm sequencing with GRAF

Specify these products

Frequently asked questions

What is a duty standby pump station?+
A duty standby arrangement uses two or more pumps so one pump can carry normal duty while another remains available for backup, alternation or assist starts under high level.
When is duty/standby specified?+
When continuity of service, authority requirements, risk of flooding or sewer surcharge, or high start frequency make a single-pump station unacceptable for the project.
Does duty/standby mean both pumps run together?+
Not always. Many stations alternate duty to share run hours. Assist or lag start can bring the second pump online under high inflow. Confirm the control philosophy on the project specification.
Can commercial pump stations include duty/standby controls?+
Yes. Control panels for commercial packages can include alternation, backup start, alarms and related sequencing when specified with the hydraulic duty.
Is redundancy available for stormwater and sewage?+
Duty/standby can apply across commercial pump stations stormwater, sewage, effluent and trade-waste packages where the project risk and specification require it.

Need a duty/standby package quoted?

Share risk requirements and duty notes. Call 1300 131 971 or use the quote form.

Request a quote