I’m trying to figure out if the Relays on the shield can take 230V AC used here in Singapore.
The front page of the relay says a maximum of 125V AC but matching the relay model with the datasheet says otherwise.
Product page:
Datasheet:
If someone has a relay shield around maybe we can match the relay model number? I don’t think the relays were changed since the first production though…
When you say the “front page” of the relay, you mean on the physical device in your hand, it is marked 125 V AC max? Then that’s the limit. If you mean on some data sheet, I would check the actual relay or datasheet.
The core doc page for the shield says 250 V max, so that seems like the spec. The relays in the picture in the doc say 125V10A which matches the datasheet too.
It labeled 10A125V on the physical relay but the matching datasheet corresponding to the part number shows that you can go for 230V range.
I’ll take it as a yes since the docs said so! 
Also assume that the current is half the rating if not stated at 250Vac.