How to power supply the Samsung VRF Gateway without the HVAC?

Good afternoon

I need to support a project which integrate the Samsung VRF device with your Room Controllers via Intesis GateWay (INMBSSAM001R100).

From the installation guide, it is mentioned that the power needs to come from VRF system F3/F4 bus, however, we don’t have the VRF system in the lab. (We only need to test the Modbus Interface between our Controller and the GW, the end to end test will be carried on site.)

  1. Is it possible to power this GW using a standard power supply?
  2. If yes, what is the supposed voltage and polarity ?

Thank you for your support.

Hello Orfuze,
Yes, that is one of the few 1:1 units that can be powered up without an AC unit.
The unit can be powered with 12 volts DC, with F4 as negative and F3 as positive.
And I always encourage you to confirm the location of your nearest fire extinguisher before trying external powering! (Kind of a joke, but never hurts to be safe).
Building Automation Applications Engineer
Intesis: OEM & Key Accounts

Hello Sean thank you very much for the answer : It is working with your solution :slight_smile
So I am to communicate with the Intesis through Modbus.
I have still few questions :

1st Question :

I am able to write without problem some registers like for example:
-99 Reset
-13 OpenWindow
-8 AC Remote…

But some like the 4 (Temp Setpoint) accept the write command but I cannot see the value changing:
It is alway -32768 even after an granted write command.
Can you confrim it is because I haven’t AC unit plug on the Intesis that the value cannot change ?

2nd Question:
I can see (-4) in the register 11 as an ErrorCode but this code is no documented. Do you know what it is meaning ?

Thank you.

Hello J-P,
Given that you are working on a development project, I would like to support your needs directly for I am your point of contact as an Intesis OEM Account Manager for some of our projects with SE.
I have sent you my contact info via LinkedIn.
Sean Gaines