Application Examples
Key for Wiring Diagram 12
eddi
device
Mains supply (230V AC from B16 circuit breaker or
13A fused spur)
Hot water cylinder
Heating element 1 (max. 3.7kW)
Isolator (20A double pole)
Relay & Sensor Board (optional add-on for
eddi
)
Temperature probe (type PT1000) (optional)
Heat Pump (with immersion heater output)
Heat pump immersion heater relay
Buffer cylinder
Heating element 2 (max. 3.7kW)
Functional Description
Some heat pump heating systems have a buffer tank for the heating circuit as well as a hot water cylinder.
eddi
can be used to make good use of any surplus generation by fully heating the water first and then heating the buffer,
allowing the maximum amount of surplus energy to be stored.
eddi
uses the Grid Sensor to monitor any surplus power that would otherwise be exported to the gird and diverts the same
amount of power to the heater loads, thereby reducing the surplus power down to zero.
For this application two heating elements are wired to the
eddi
; the water immersion heater (4) is connected to Heater 1
output and the buffer tank immersion heater (11) is connected to Heater 2 output. Priority is given to the water heating and
only when fully heated does the
eddi
switch to heating the buffer tank.
Most heat pumps require control of the immersion heater in the hot water cylinder, this is to periodically heat the water to
a higher temperature in order to kill any Legionella bacteria that may have built up in the stored water. Remember it is not
permissible to 'back-feed' the
eddi
device; a voltage supply must not be connected to the heater outputs. Because of this,
the heat pump immersion heater relay (9) needs to be connected to the eSense input of the Relay & Sensor Board (6)
instead of the immersion heater element (4). In this application, the
eddi
is configured to respond to the eSense signal by
fully switching on Heater 1 output regardless of available surplus.
Installation of the temperature probes (7) is optional; the heaters' mechanical thermostat can be used instead if
temperature readings are not required.
Settings Required
Menu Option
Settings
Main Menu
Settings…
Display…
Icons…
Heater 1:
Top Immersion
Heater 2:
Radiator /
Underfloor Heating
Priority…
Heater 1
Advanced Menu…
Relays &
Sensors…
Temperatures…
Set Temperatures as
required if using
temperature probes
eSense Input…
Boost…
Boost 1
operation and installation manual
eddi
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