-
12
-
-
13
-
6 . The flexible hose and any wiring can be retained in the desired position
using cable ties and the two metal cable retention points on the top left
and right of the APU tank . See Figs . 10 & 11 .
7 . The warning pipe should be connected to a suitable drain via a tundish
enabling visual warning of an overflow condition . The overflow fitting is
designed to use 19 to 23 mm diameter plastic waste pipe or connect to
G ¾ threaded pipe . Ensure there is a demountable joint in the pipe to
allow the removal of the APU Midi if needed .
8 . Non-return valves, pressure reducing valves and RPZ valves
MUST NOT
be installed between the APU Midi and the heating/cooling system . These
devices will prevent the pressure sensor from reading the system pressure
and will lead to incorrect operation of the unit .
9 . The APU Midi should be connected to the system return header along with
the expansion vessels as specified in BS 7074 . See Fig . 12 .
4 .16
Typical installation diagram:
4 .17
Vessel sizing & location:
1 . System expansion vessel sizing should comply with the BS 7074 Expansion
Vessel sizing calculation .
2 . The pressurisation unit and expansion vessels should be connected to the
system at the same point, to provide a neutral pressure reading .
3 . A lockshield valve and drain valve should be installed at the inlet of each
expansion vessel to allow for servicing .
5 ELECTRICAL INSTALLATION / EARTHING
5 .11
Regulations: The electrical installation must be carried out in
accordance with the current national electrical regulations and
installed by a qualified person .
5 .12
Safety: In the interests of electrical safety a 30 mA residual current
device (
R.C.D. not supplied) should be installed in the supply circuit .
This may be part of a consumer unit or a separate unit .
5 .13 Before starting work on the electrical supply ensure power supply is
isolated .
5 .14
DO NOT allow the supply cord to contact hot surfaces, including the
motor shell, pump body or pipework . The cord should be safely
routed and secured by cable clips .
5 .15
Adjacent pipes: Adjacent suction and delivery pipes should be fitted with
earthing clamps in accordance with current regulations (Fig . 14) .
5 .16
Earthing: This appliance must be earthed via the supply cord .
5 .17
Pipework: Copper or metallic pipework must have supplementary earth
bonding where the continuity has been broken by flexible hoses or plastic
components .
5 .18
Additional earthing: Certain installations may require additional earthing
arrangements such as equipotential bonding . Reference should be made to
the relevant regulations concerning this subject to ensure compliance .
5 .19
Connections: The APU Midi must be connected to a dedicated fused SPUR via
a lockable isolator to avoid unauthorised disconnection .
5 .20 The electrical connection
must be made adjacent to (not behind) the APU
Midi to allow disconnection of the electrical supply should the pump module
need to be removed for service or maintenance .
Fig . 12
Fig . 13
APU Midi
Warning pipe
Drain
valve
Isolation
valves
Expansion
vessel
Return
header
Lockshield
valve
Drain valve
Earth continuity
connection
Fig . 14
Flexible
hoses
Metallic
pipework
