Is "TT Switch" an appropriate generic term for these?

Is "TT Switch" an appropriate generic term for these?

  • Yes: I've heard or use the term, and that's what it meant.

    Votes: 0 0.0%

  • No: Could be anything, better make up a symbol and describe what you mean in the legend

    Votes: 2 100.0%

  • Other: I've heard the term, but it did not or may not mean what you think it means...

    Votes: 0 0.0%
  • Total voters
    2
  • Poll closed .
Status
Not open for further replies.
R

RASanders

Member
Location
Illinois
When noting the requirement for a service disconnect switch for a motor or pump, small single-pole equipment often ends up with just an 'HP-rated' toggle switch.

However, if I want to ensure thermal overload protection for equipment that may or may not have this integrated in the motor, or would consider this a manual 'starter' switch, I don't necessarily want to require a sole-source such as "Shall install Siemens SMFF series."

I've heard at least one contractor refer to 'those TT Switches' and assumed this meant "Thermal-overload Toggle" switch, but cannot seem to find an industry reference to "TT Switch" being a recognized standard nomenclature for them.

Can anyone confirm?
 
Never heard TT, and Switches for small loads like this are usually an "S", then with a sub-text notation like TH for "thermal" or MTR for "motor". It's actually best to not assume anyone knows, just put in a legend.

switchsym1.JPG
 
They are a manual motor starter with overloads. It can't really be represented on a floor plan without a corresponding symbol legend to clarify it, but that is even true with GFI's counter top recepts, quads etc. Something I have seen typically is Sm for a motor rated toggle switch and Sms for a starter. Or sometimes MMS The legend or a mechanical schedule will usually explain whether the starter has overloads and/or a pilot light.
 
Status
Not open for further replies.
Top