zappi
32
operation and installation manual
Installation
Advanced Installation Options
Load Balancing / Current Limiting
CTs can be also used to the limit current drawn by
myenergi
devices to avoid overloading circuits. this is sometimes referred to
as load balancing. There are four different ways to limit current and they can be used alone or combined for more complex
situations. See the table below:
Function
Operation
Example
Device Limit
Sets a maximum current that can be drawn by the
device (e.g.
zappi
). The current will not be
exceeded even during Boost or Fast charge.
A
zappi
is wired to a 20A supply (rather than a
32A). The maximum current drawn will not exceed
the set limit (e.g. 20A).
Grid Limit
Sets the limit that can be drawn from the grid
connection (i.e. the maximum import current). The
zappi
and any other linked
myenergi
device, will
limit the current they draw if there is a danger of
exceeding the set Grid Limit.
A property may have a grid supply limit of only 65A,
several appliances are on and the property is
consuming 12kW (52A) by other appliances and the
user wants to charge in FAST mode. With a Grid
Limit setting of 60A,
zappi
would temporarily
limit the charging current to 8A (about 1.8kW) and
the maximum allowed import current would not be
exceeded.
Group Limit
(internal CT)
Sets the combined current limit for several
myenergi
devices.
A property has a large PV array and a swimming
pool, three
eddi
units are installed to heat the pool
with surplus solar power using 3kW heaters. The
supply for the eddi units is only 40A, to be safe a
Group Limit of 35A is set.
Group Limit
(with external CT)
Sets the combined current limit for several
myenergi
devices that are sharing a supply with
another large appliance.
An
eddi
is installed to heat the hot water cylinder
in a garage which also has a washer and a dryer
(2.5kW each), the garage has a supply of only 32A
coming from the main consumer unit in the house.
If all appliances were on and there was no limiting
set, the total current would exceed the maximum
supply current.
Battery Storage Systems
AC coupled
Where there is an AC coupled battery storage system, there can be a conflict as both the storage system and the
zappi
are
effectively competing to consume the surplus energy. Whilst this is not necessarily an issue, the results can be somewhat
unpredictable.
There is the option to add an additional CT sensor to monitor the battery storage; this will give control as to which device has
priority. This additional CT sensor should be wired to one of the CT terminals of the
zappi
This CT should be clipped
around the live or neutral cable of battery inverter.
During the setup process it will be necessary to change the setting for the appropriate CT to AC Battery; refer to
(page 21). for information on setting 'priority' of battery systems.
