When it comes to wiring a Lionel KW transformer, there’s more to consider than just which posts to use. The size of the wires also matters. If you derail a train 8 amps of power can run through the wire for 10-15 seconds before the circuit breaker kicks in. You don’t want the insulation to melt and catch fire.
Proper wiring for the KW transformer is a bit of a safety issue.