Hi All

Can anyone explain the Dry Contact Terminal, specifically the term MOS below...

Thanks

Mark

3 hours ago, Mark said:

MOS below...

MOS normally reference to metal-oxide-semiconductor, like in a mosfet. In plain terms, a metal gate in a transistor used to switch something. 

EDIT, I might be wrong, but that is the way I remember it. 

MOS = MOSFET

When you are overcharging the Pylontech, it informes you via this terminal and if you will continue charging anyway then a few seconds later it disconnects itself using the built-in MOSFET.

The discharging process has a similar behavior.

On 2019/09/06 at 4:23 PM, Mark said:

Can anyone explain the Dry Contact Terminal

In this case you can use these contacts to switch certain load on and off. 

You can use output 1 to control a contactor on the load, if the BMS decides the batteries should not be discharged any further the  MOS will switch off, the contact opens and the contactor falls out, disconnecting the load. 

output 2 can be wired to a charge controller's "External" connection, so when the batteries requires to be charged the contact will close and tell the controller to start charging the batteries. 

Output three, can be used to switch on a siren or indication light to indicate there is a fault. 

In Laymans terms a dry contact is a contact that has no voltage on it, you need to supply a voltage to the Common point and when the contact closes, it will return that voltage to you to be used for switching the contactor or light or siren. 

Has anybody actually used these dry contacts successfully ?

I measured a 4VDC between the (in+ and GND).  

The other three contacts seem to always be in NC state, do they switch to NO position only if the Pylontech experiences a alarm or fault condition or are they programmable with some software?