Controlling External Components; Charge Relay; Load Relay - 123electric Smart BMS gen 3 Manual

Controlling external Components

The End Board contains two signal relays with
three potential free contacts (normally open,
common contact, normally closed) to control
external components of your off-grid system.
This can be "solar chargers", "Maximum
power point trackers", "inverters", etc. An
example is the "enable" pin on many
inverters. Otherwise you can connect an
energy efficient power relay which can control
the battery power supply to the
charger/inverter. The maximum current
through the signal relays is specified in section
"Specifications".

Charge relay

There is one relay to control incoming energy
components of the system, like MPPT, solar
charger et. This relay is called the "CHARGE"
relay. When charging is allowed the green
CHARGE LED next to the CHARGE relay will
flash every second.
When charging is allowed Pin 1 and 2 of the
CHARGE relay contacts (see End Board details)
are closed (pin 2 & 3 are open).
When charging is NOT allowed Pin 2 and 3 of
the CHARGE relay contacts are closed (pin 1 &
2 are open).
Note: when switching inductive loads like a
relay/contactor, make sure there is a
protection against flyback of the coil. A
simple example is the flyback diode parallel
to the coil.
123electric
The Netherlands
E-mail: info@123electric.eu
www.123electric.eu

Load relay

The other relay is to control outgoing energy
components of the system, like inverters or
other consumers. This relay is called the
"LOAD" relay. When discharging is allowed the
green LOAD LED next to the LOAD relay will
flash every second.
Note: when switching inductive loads like a
relay/contactor, make sure there is a
protection against flyback of the coil. A
simple example is the flyback diode parallel
to the coil.
The 123\SmartRelay, Victron BatteryProtect
and Kilovac EV200 relays do not need a
separate flyback protection.
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