Toroidal transformer output windings in parallel

[KMN1]

Is it safe to to parallel the output windings of a transformer like this one https://uk.rs-online.com/web/p/toroidal-transformers/7529410?
Such that the output voltage is 24Vrms with a maximum power rating of 500VA (~20Arms maximum)?

If so should the wires with a dot annotation be connected together to form this parallel circuit, with red and grey also connected in series?

 

[Easy peasy]

Yes - but if even one turn out there will be high currents - so power up the primary and use a good DVM to measure the sec voltages - if they are exactly the same - then you can parallel;

dot to dot, the easy way to check this to to put the sec's in series and measure the total voltage - if you get near zero you have two dot ends already connected and can safely connect the two remaining ends - if you get 2 x Vout - sec, you have a dot connected to a non-dot.

 

[KMN1]

Yes - but if even one turn out there will be high currents -

Sorry do you mean i should use only one secondary winding first?

Yes - but if even one turn out there will be high currents - so power up the primary and use a good DVM to measure the sec voltages - if they are exactly the same - then you can parallel;

If the voltages are not exactly the same what would happen? is there a tolerance for which the voltages can deviate?

What's the safest method to measure the voltage? should a load resistor be placed or is open measurement of the voltage with DVM fine?

 

[FvM]

The discussion about "exactly the same voltage" is rather sophistic. The technical criterion to allow parallel connection is same nominal voltage respectively same number of turns. That's obviously the case for the linked transformer. Primary as well as secondary windings can be parallel connected if necessary.