matson MA98411, Manual

AUTOMATIC LOAD SWITCHING

The MPVSR can be programmed to perform automatic load switching, 

by using the control terminals for sensing a desired voltage range. This 

is particularly useful in remote or unmanned situation where equipment 

needs to be operated, but also protected from over-voltage and under-

voltage damage scenarios. For example, a flashing light on a remote 

tower needs to be activated at night, but it is powered by a lithium battery 

bank that is very expensive. Wiring the light switch in series with the 

control terminals (positive or negative) and setting the upper and lower 

voltage limits to the desired range means that the light can be switched on 

and off as needed, but only if the battery voltage is within the safe range 

set by the user.
Setting Guide: (note, this setup requires the MPVSR bet programmed 

‘normally open’)
UPPER LIMIT IN VOLTS: This is the setting where the voltage would be 

re-connected to the light to allow it to operate as required again. In this 

example it would be the safe voltage level for the batteries to operate 

again.
LOWER LIMIT IN VOLTS: This is the voltage level at which the light 

would be disconnected from the power source so as not to over-discharge 

the battery bank. This setting would be determined by the battery 

manufacturers guidelines.
UPPER DELAY IN SECS: This is the delay setting for re-connecting the 

load to the power source. Delaying the re-connection allows the voltage at 

the power source to stabilise before the load is connected again.
LOWER DELAY IN SECS: This is the delay, in seconds, before the power 

is disconnected from the light after the voltage reaches the LOWER LIMIT 

IN VOLTS. A delay here can be useful to prevent VSR chatter due to 

transient voltages and slight dips in power levels.