High temperature terminations

Discussion in 'General Electronics Chat' started by inwo, Jun 19, 2014.

  1. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    I've been consulted for an oven problem.
    Melting connections.

    Oven has a number of 650 watt ceramic elements over a conveyer.

    Above the heaters is a sheet metal shield with ventilation top and bottom to outdoors.

    I mention this, as first assumption is, area above shield is lower than the 400C operating air temp below.

    Heaters are interconnected with aluminum buss bars ~1/8" X 3/4".
    Plain cad plated hardware to brass terminals and steel? (magnetic) wire.

    First thoughts are to clean aluminum surfaces and use stainless hardware.

    As an electrician, I like to use oxide inhibitor on aluminum.
    I don't know the temp. limitations.

    Until oven is operating I won't know temp. above the heating area. I'll have to assume 400C . Same as set temperature.

    Some wires are loose in the factory crimped terminals.
    The wire actually wiggles inside the brass crimp. (2nd picture)
    Once corroded I don't know if there is a solution. Silver solder/brass?
    I guess brass is out if terminals are brass.:p
    A could use plated steel terminals and braze.

    Also thinking of copper buss or an overlay of bare copper #10awg.
    If I start mixing cu. and al. there will be issues.:eek:
    Last edited: Jun 19, 2014
  2. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013