Installation Indirect - Jet 120i Installation & Servicing Instructions Manual

Installation - Indirect
Safety
DISCONNECT FROM THE MAINS ELECTRICAL
SUPPLY BEFORE REMOVING ANY COVERS.
Never attempt to replace the immersion heater other
than with the recommended authorised immersion
heater.
DO NOT BYPASS THE THERMAL CUT-OUT(S) IN
ANY CIRCUMSTANCES. Ensure the two male spade
terminations on the underside of the combined
thermostat and thermal cut-out are pushed firmly
onto the corresponding terminations on the element
plate assembly.
In case of difficulty contact service support; contact
details available at the back of this booklet.
Electrical Supply
All electrical wiring should be carried out by a
competent electrician and be in accordance with
the latest I.E.E Wiring Regulations.
Each circuit must be protected by a suitable fuse
and double pole isolating switch with a contact
separation of at least 3mm in both poles.
The immersion heater should be wired in accordance
with Fig 07, opposite. The immersion heater MUST
be earthed. The supply cable should be 1.5mm
core HO5 VV-F sheathed and must be routed through
the cable grip provided with the outer sheath of the
cable firmly secured by tightening the screws on
the cable grip.
DO NOT operate the immersion heaters until the
cylinder has been filled with water.
Ensure the thermostat and thermal cut-out sensing
bulbs are pushed fully into the pockets on the element
plate assembly.
Plumbing Connections
Indirect cylinders require the following
pipework connections.
• Cold water supply to and from inlet controls.
• Outlet to hot water draw off points.
• Discharge pipework from valve outlets to
tundish.
• Connection to the primary circuit.
All connections are 22mm compression. However,
3/4"BSP parallel threaded fittings can be fitted to
the primary coil connections if required.
12
Boiler Selection
The boiler should have a control thermostat and non
self-resetting thermal cut-out and be compatible
with unvented storage water heaters. Where use of
a boiler without a thermal cut-out is unavoidable a
"low head" open vented primary circuit should be
used. The feed and expansion cistern head above
the cylinder should not exceed 2.5m.
Primary Circuit Control
The 2 port motorised valve supplied with the cylinder
MUST be fitted on the primary flow to the cylinder
heat exchanger (coil) and wired in series with the
indirect control thermostat and thermal cut-out fitted
to the unit. Primary circulation to the cylinder heat
exchanger (coil) must be pumped; gravity circulation
WILL NOT WORK.
Space and Heating Systems Controls
The controls provided with the cylinder will ensure
the safe operation of the unit within the central
heating system. Other controls (eg. room thermostat
and timer) will be necessary to control the space
heating requirements and times that the system is
required to function, (see Fig. 07 below). The cylinder
is compatible with most
of electrical circuits are shown in Figs. 08 and 09
(Page 13). However, other systems may be suitable,
refer to the controls manufacturers' instructions,
supplied with the controls selected, for alternative
system wiring schemes.
3
2
Control Housing Details
Element Connections
Indirect control
wiring
Figure 07: Electrical Connections (indirect schematic)
heating controls, examples
1 2 3 L N
1.5mm² 3 Core
HO5 VV-F sheathed
cable