GL0016P-02 Installation Guidelines for BioDisc
®
Units BF, BG, NF & NG
8
5.11 Place concrete backfill to approximately 500mm depth around the unit ensuring good compaction to
avoid voids.
Do not use vibrating pokers.
5.12 Continue backfilling with concrete up to the level of the outlet. Keep the concrete at an even level all
round the unit, compacting in layers. As backfilling progresses keep the ballast water level inside the
unit 250-500mm above the concrete backfill level, but do not attempt to fill the unit with water above
the outlet level.
5.13 BG and NG only: Ensure that concrete is fed into the area between the two casings to eliminate voids
as far as possible and assist in anchoring the unit.
5.14 Connect the inlet and outlet pipework when safe access can be gained. Short lengths of “rocker” pipe
with flexible joints should be used adjacent to the unit to allow for any minor differential movement.
5.15 Check the cables attached to the control panel and drill the corresponding number of 40mm holes in
the BioDisc case, 100mm below ground level and adjacent to one end of the interior walkway. If an
Independent Remote Alarm is to be fitted this will also require a 40mm hole.
5.16 Erect the Control Panel as described in Section 6.0.
5.17 Continue backfilling to ground level with concrete, pea shingle (3-18mm), or similar non-cohesive,
non-compressible free-flowing granular material.
Do not use sand.
The finished surface should be
65mm minimum lower than the lip of the cover.
5.18
Important : Read section 8.2 regarding delayed electrical installation
.
6.0 Control Panel Installation
6.2. General Installation
6.1.1. The control panel should be positioned adjacent to the unit, so that:
a) It does not interfere with cover removal.
b) It is convenient for the incoming power supply.
c) It cannot be reached by someone standing in or on the BioDisc unit.
d) It is close enough to enable the electrical connections to be made in the BioDisc.
This usually indicates a panel position about 1.5 metres distance from the BioDisc, adjacent to the
inlet or outlet.
6.1.2. Set the panel leg(s) in a concrete base, minimum 250mm thick and prop the panel to prevent
movement until the concrete has set. Allow 350mm minimum clearance from ground level to the
bottom of the panel.
6.1.3. Control panels are supplied with pre-fitted steel wire armoured (s.w.a.) cable(s), complete with
grommets and glands. Lay the cable(s) in a 500mm deep trench and bed them on a layer of sand or
similar soft material.
6.1.4. Insert the cables through the hole(s) in the casing of their respective unit(s), using the grommets
supplied. Leave the cable(s) temporarily secured above water level pending electrical installation.
6.1.5. Cover the cable(s) with a layer of sand or similar soft material and warning tape. Backfill the cable
trench with graded spoil, free of large stones or any other material which might damage the cable(s).
6.1.6. The Control Panel key is in the protective bag at the end of the motor/gearbox cable.
6.2. Electrical
Installation
6.2.1. Depending on type, the control panel is supplied with between one and three pre-fitted armoured
cables.
a) Every Control Panel has a motor/gearbox cable.
b) Control Panels for NF, NG and BG units have an additional Sludge Return Pump cable.
c) Alarm Control Panels have an extra cable for the Loss of Rotation sensor.
Each cable is fitted with a gland for connection to the terminal box or junction box and a grommet for
entry into the BioDisc case.
