My system with a lynx distributor has 3x Multi RS 6000 and 1x SmartSolar RS 450/200 connected to it. The Multi RS’es are equiped with 200A fuses and the 450/200 has a 250A fuse.
All use 70mm2 DC cables.
My question is what the maximum allowed operating temperature of the Lynx system is.
The specs show that the lynx is rated for 1000A continues, however my system is running at 350A load for long durations (5+ hours per day).
I have a temperature probe connected to the positive busbar and I am reaching temperatures of 55 degree C on the busbars.
As the lynx distributor is almost completely sealed without any ventilation holes, I was wondering if this is normal or concerning.
PS: I have just switched from Victron Mega fuses to Adler EF3 fuses since these have a much higher breaking capacity (50kA vs 2kA on Mega fuses). However the temperature is the same with either fuse.
55C rise over 50C ambient is the standard determination of busbar ampacity according to IEEE, though notably other manufacturers sometimes rate lower to account for higher ambient temperatures - Blue Sea, for instance, determines their busbar ampacity by a 40C rise over ambient.
Your Lynx reaching 55C is not itself a cause for concern unless your ambient is 0C, which seems doubtful but in which case I’d say there might be an indication of a loose connection somewhere that’s causing high heat.
You can search and find others that have come to the same conclusion.
I and at least a few others have challenged Victron about this and requested to remove the 1000A continuous from the manuals. At the very least I would like them to change continuous to intermittent, but I think the right answer is 500A continuous as the products are delivered (without modification). However, they have tens of thousands of Lynx products out there that have 1000A screen printed on the lids, so changing to 1000A intermittent would be a good step.
Okay, so that’s only a 30C rise over ambient while running 350A continuous through it, I wouldn’t consider that concerning. As Ed has correctly pointed out, the “1000A” rating is… er… optimistic… but you’re well within spec still.
