Installation at a Glance

Before installation

• Installation should only be carried out by a qualified specialist.
• Check the ground conditions, soil type, water table and potential flood risk before excavation.
• Confirm the proposed location has been approved by the relevant Building Control/local authority where required.
• Check the tank, pumps, pipework, control equipment and accessories against the delivery note before installation.
• Plan sufficient access for excavation equipment, concrete delivery and removal of spoil.

Choosing the location

• Keep the pump station away from areas where it could be subjected to additional loading.
• Harlequin recommends that vehicles and other superimposed loads are kept at least 3 m from the tank.
• If vehicle loading within this area is unavoidable, a qualified civil/structural engineer must design and sign off the installation.
• Consider the tank invert, inlet drain gradient and surrounding ground levels when selecting the location.
• Where a drainage field is used, the guide recommends minimum distances of 15 m from a habitable dwelling, 10 m from a watercourse and 50 m from a well/drinking water source.

Excavation & concrete base

• Check the excavation is suitable and stable before installation.
• All Harlequin Pump Stations require a minimum 150 mm concrete base and 300 mm of concrete around the tank.
• The concrete base should be 25 N/mm² strength, with a 30 mm slump, and levelled to within 20 mm.
• On difficult ground such as unstable ground or shrinking clay, additional excavation may be required for hardcore and sand blinding.
• The tank must be installed true and level.

Positioning & lifting

• Tanks must only be lifted using the designated lifting points and when completely empty.
• Do not use chains or wire ropes for lifting.
• Avoid sharp impacts during handling.
• Once positioned on the concrete base, check the tank is level before proceeding.

Installing the pumps

• Install the pump(s) and internal pipework before filling the tank or connecting the inlet pipework.
• After installing the pumps, fill the tank to at least 600 mm water depth, or to the maximum inlet-pipe level, before connecting the inlet.
• On twin-pump systems, ensure all float switches are correctly positioned and can move freely.

Concrete backfill

• Carefully place concrete beneath the lower radii of the tank to ensure it is fully supported.
• Do not use a vibrating poker.
• Continue filling the tank with water while placing concrete around it.
• The water level inside the tank must always remain higher than the external concrete backfill level.
• Make sure there are no voids in the concrete around the tank.
• Fill the tank to the level of the outlet pipe and bring the concrete up to approximately 200 mm below this level.
• Allow the concrete to harden for approximately 24 hours before continuing.
• Once hardened, connect the outlet/service pipes and continue the concrete backfill to approximately 50 mm below finished ground level.

Pipework

• Recommended drain gradient into the pump station is 1:40. A gradient of 1:80 may be permitted with Building Control approval.
• Check all inlet and outlet pipework is correctly installed and free from obstructions.
• If drains are shallow or pass beneath walls/foundations, additional protection such as concrete surrounds may be required.

Electrical installation

• Electrical work must only be completed by a fully qualified electrician.
• The standard requirement is a single-phase 240 V supply via 3-core steel-wire-armoured cable.
• The pump station should have a dedicated electrical circuit with appropriate isolation and protection.
• Refer to the specific pump/control-panel instructions for the required cable size and electrical rating.

Ventilation

• A dedicated venting point is required to allow the pump station to vent safely.
• The system should vent via a soil stack extending to the top ridge of the dwelling.
• The vent should not terminate at eaves level.
• The ventilation route must allow air from the pump station to pass back through the inlet pipework to the soil stack.

Commissioning

• Check tank seals and connections for leaks while filling.
• Check inlet and outlet pipework is correctly installed and unobstructed.
• Confirm all float switches are connected correctly and positioned at the correct heights.
• Floats must not sit on the bottom of the tank.
• On twin-pump systems, make sure floats hang freely and cables are not tangled.
• Test the float switches and pump operation.
• Confirm the tank empties correctly after the initial pump cycle.
• Refit and secure the manhole covers.