Heat Pumps and Electric Heating - Aux heat wiring for Trane Heat Pump system

I'm looking for the ideal way to wire up my electric heater to ensure comfort and efficient power use and support for the emergency heat mode. I have a Trane TWE030C140A1 air handler with BAY96X141002 electric heater and XE1100 heat pump (don't know the exact model off hand, but I can get it if necessary). My White-Rodgers 1F82-261 thermostat is connected as follows:

Thermostat - Air Handler - Heat Pump (purpose)
R - R - R (24 VAC)
C - B - B (common)
G - G (fan)
O - - O (cool changeover)
Y - - Y (compressor)
W2 - W1+W2 - X2 (heater)
E (not connected) (em heat)
L (not connected) (system monitor)
W3 in the air handler is not currently connected.

1) Of W1, W2, and W3, which should be attached to W2 (aux heat) on the thermostat?
2) Of W1, W2, and W3, which should be attached to E (em heat) on the thermostat?wasn't
3) Where should X2 (defrost) from the heat pump go?

I've already learned a lot from this forum, but I'm still not sure how to use the three separate heater leads.

Thanks.

I
1) Of W1, W2, and W3, which should be attached to W2 (aux heat) on the thermostat?
W1


2) Of W1, W2, and W3, which should be attached to E (em heat) on the thermostat?wasn't
W2

3) Where should X2 (defrost) from the heat pump go?
Is there an outdoor sensor on the unit itself outside?

Thanks for the reply, Jay. Yes, the heat pump has a sensor and kicks into defrost mode when necessary. When it does that it has to be able to turn on the aux heat so that it's not blowing cold air into the house. Right now that wire is connected to W1 and W2 on the air handler (which are also connected to W2 on the thermostat).

The way it's wired right now, we don't have emergency heat, and it uses both W1 and W2 on the electric heater for aux and defrost heat. W3 is never used; should it be?

Not the defrost, the outdoor temp sensor to tell the heat pump it's too cold to run, turn on aux heat to keep up.

There is a brown wire labeled T1 in the heat pump but it's disconnected right now, but I'll bet it's a temperature sensor. Where should this connect to? There's a T lead in the air handler, but according to the diagram on the unit, it's not wired to anything. Thanks again for helping me out.

Leave the T wire alone, that is not used with your t-stat, it's only for the Trane's t-stat.

The outdoor sensor will have a probe/control wired to BK/X2 outside..

sounds like you don't have an outdoor sensor.

so wire X2 to W3, and jumper over to W2.

OK, so here's what I have now:

W2 thermostat - W1 air handler
E thermostat - W2 + W3 air handler -- X2 heat pump

So emergency heat will power W1, W2, and W3 on air handler and heat pump defrost will power W2 and W3, while normal aux heat will power W1 only.

Thanks!

I don't know that brand of t-stat that well what the cycle is...

I know on the Honeywell, when in Emr Heat mode, it will stage between W1 and W2. and In aux, it will also stage between the two as well.