VRF system low demand issues

[Robocool]

Evening all

has anyone come across any issues arising from connecting tiny 1.5/2kw units on to a large (100kw) VRF system. We have a few on a system serving small 2m2 rooms and we suspect, when only one is operating in auto, the FCUs changeover too quickly and the system trips out.

There are several cassettes on the system, the majority are 10KW units but around five of them 2kw units at the very end of the piperun. Like distances all check out and the system runs beautifully when all units are in demand.

any advice anyone may help would be much appreciated.

[The Viking]

Sorry Robocool,

We do need a bit more information to go on for us to be able to comment.

Generally, older VRV/VRF systems needed a minimum load to operate whilst newer systems are better at coping with low loads.
So, if you give us make/model/age we can better advice you.

[Robocool]

It's an LG heat recovery VRF installed last year. Condenser is a 3 module ARUB520 with about 25 indoor units. Several of these are the 1.6KW Mini Cassettes.

System trips out on CH151 fault every so often but we can never find anything wrong with the system

[The Viking]

OK,
Sorry, I never worked on LG's VRFs so don't know their control strategies.

Hopefully someone more knowledgable will see this thread shortly.