TC-EC wire in conduit to disconnect for mini split?

[archibald tuttle]

adding multiple threads notably here on TC-ER to minisplits and elsewhere on multi-wire cable in conduit I think I'm reaching the conclusion that if you want to run a single 3 wire cable without junction from the breaker panel to the service disconnect where there is any run outdoors to reach the disconnect TC-ER could be a good choice because of its outdoor rating but it should be run in conduit to the disconnect in a size of conduit that observes the lower fill allowances? Of course I like that from an appearance standpoint although I'm not 100% clear given the additional crush ratings which appear to be oriented at allowing a support last whip out of cable tray would militage against simply fastening exposed TC-ER under the house skirt for instance. And along with outdoor rating it otherwise exceeds the characteristics of romex to be run exposed indoors on the same basis with support so I can see why this cable was a focus of installers.

so if HVAC installers have this cable, then the question also appears they have been inappropriately making it the 'last mile', i.e. exposed feed whip from the disconnect to the heat pump itself, most often cable tieing to line sets for support.

again, observing fill limits, a conduit run could accomodate this although if I understand the purpose and rating of the cable it does appear that if a manner of support were provided, e.g. piece of pressure treated 2x4 between house and installation pad that it can be used outdoors. I mostly find the discussion technically interesting as various waterproof whips that clearly fit the outdoor exposed use don't seem like a big headache since you are stopping at a disconnect close to the unit anyway. So I'm mostly focused on the run from the panel to the disconnect.

thanks,

berian

 

[tortuga]

to run a single 3 wire cable without junction from the breaker panel to the service disconnect where there is any run outdoors to reach the disconnect TC-ER could be a good choice because of its outdoor rating but it should be run in conduit to the disconnect in a size of conduit that observes the lower fill allowances?

Tray cable can be installed outdoors at one and two family dwellings, it has to be 'TC-ER-JP' installed per the same rules as UF cable, see Article 336.10(9)