Single Element Immersion Heaters; Dual Element Immersion Heaters; Twin Immersion Heaters; Commissioning Instructions - Horstmann electronic 7 Installation Manual

Single Element Immersion Heaters

The 3 core flexible cord should be heat-resistant and rated to 85°C.
TERMINAL 4 (Boost live output) should be connected to TERMINAL 5 (Off-Peak
live output) and to the immersion heater.
The Neutral connection should go to TERMINAL 3 and the Earth connection to the
EARTH TERMINALS.

Dual Element Immersion Heaters

The elements should be controlled through separate thermostats. In practice the
thermostat for the top (short) element is usually set 5-10°C less than the thermostat
for the long Off-Peak element. The 3 core flexible cords should be heat-resistant
and rated 85°C.
TERMINAL 4 (boost live output) should be connected to the short element and
TERMINAL 5 (Off-Peak live output) to the long element.
The Neutral connections should go to TERMINAL 3 and the Earth connection to the
EARTH TERMINALS.

Twin Immersion Heaters

The thermostat for the top immersion element should be set lower than the
thermostat for the bottom immersion heater.
The 3 core flexible cords should be heat-resistant and rated 85ºC. TERMINAL 4
(boost live output) should be connected to the top immersion heater and TERMINAL
5 (off-peak live output) to the bottom immersion heater. The two Neutral connections
should go to TERMINAL 3 and the Earth connections to the EARTH TERMINALS.
When wiring is complete ensure that all terminal screws, including the earth terminal
screws are securely tightened to achieve a minimum torque of .75Nm.

Commissioning Instructions

The commissioning switch is on the rear of the unit (once removed from
the back box) and must now be set to achieve the correct operation of the
controller and to engage the BATTERY RESERVE. The display will remain
blank with the switch in the "OFF" position.
It is essential that the correct commissioning switch position is selected. Incorrect
setting of the commissioning switch may result in inefficient use of the available off-
peak supply. On installation the installer needs to select whether the Electronic 7 will
switch at GMT times throughout the year or whether the timings need to alter as the
clocks change.
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