Transformer - Output = 24 volt AC at 1660mA ,
Rainsoft PN = OTE-40-24-ACDC-N PTC, also referenced as PN 17000.Transformer cord-with special fittingsold separately ( Cable - Rainsoft 2 wires 18 AWG and Connector = PN RS92616A )
NOTE: There is not "+" or "-" ( polarity ) on this or any other AC ( alternating current ) transformer.
Polarity only applies to DC ( direct current transformers ).
Also NOTE: Older models had a 3rd wire ( Center - Ground )
as referenced in our alternate photo.
This is no longer used,
and was never "necessary".
None of the 24 AC transformers sold for water softeners has a "Ground" on them.