Cristec VLTG-70 Voltage Guard
The Cristec Voltage Guard protects a battery from excessive discharge and will also protect consumers from overvoltage. The VLTG-70 can handle current flow of 70A.
When your battery reaches a pre-set low voltage, the Voltage Guard will disconnect the loads from the battery. It will automatically reconnect them once the battery has been charged back up to a pre-set voltage. The unit will do the same to protect consumers from a very high source voltage.
So, if you forget to turn off lights (or other non-essential consumers) in a cabin, leaving them to drain the battery; they will be disconnected automatically preserving battery energy for essential tasks. Once charging resumes, there is no need to turn the systems back on - they will automatically be reconnected.
The low voltage threshold is adjustable using dip switches, but the high voltage setting is fixed.
Voltage Guard has an LED and buzzer to alert you of its status. It can also be used as a remote switch (high voltage protection is disabled when using this function).
Overview
The Cristec Voltage Guard unit is a very useful tool for managing the potential for accidental deep discharge of service batteries on DC systems.
On simple systems it may be enough to manually turn off consumer groups or even consumers individually but on larger vessels the potential to lose a lot of battery power without noticing is greater and some form of automation is helpful.
Consider these devices as automatic load-shedding relays. If a number of them were used in a system, they can even be configured to disconnect loads at varying levels of battery discharge to a point where only critical navigation and communication units remain connected.
Specs
Voltage - Automatic (12V - 24V)
Current Capacity (cont.) - 70A
Current Capacity (peak) - 140A