Thank you all for your advice. It is clear that this module is not safe enough to use in the way I envisaged. I am now tending towards using wireless remote control modules. Twenty feet of air, even humid air, is a damn fine piece of isolation. :-) __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb *Sent from my etch-a-sketch* On 20 July 2018 at 08:30, RussellMc wrote: > That looks good as an example - BUT: any add on solution needs to be > checked to ensure that it fixes the isolation issue and does not have > issues of its own. > > Russell > > > > On 20 July 2018 at 11:22, Allen Mulvey wrote: > > > While looking for something else I came across this: > > Enclosed Pre-Wired Relay > > https://www.ebay.com/itm/RIB-Functional-Devices-RIBU2C-Enclo > > sed-Pre-Wired-Relay-120-277VAC-10A/282946266423?epid=3D2261035 > > 387&hash=3Ditem41e0e96537%3Ag%3AkTIAAOSwqxRa52aB&_sacat=3D0&_nkw > > =3Denclosed+pre-wired+relay&_from=3DR40&rt=3Dnc&LH_TitleDesc=3D0 > > > > Use the 555 module to switch this one as Russell suggests. > > > > Allen > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .