We recommend impulse transformers for power supply of glass blocks. The glass blocks supply voltage must not exceed 12.5VDC. For connection of glass blocks we recommend to use single LgY copper cables (cablet type), P.V.C. insulated, size 1,5mm2; the outer diameter of cable insulation must not exceed 3,5mm. The best way to mark the supply polarization is by using colour cables – for example red cable (+) and black cable (-). The glass block voltage polarization has been marked with colours: red (+) and black (-). End of supply circuit (ends of transformer cables) has to be protected against humidity with an insulation tape (best self-vulcanizing) – you should not build a loop for this circuit, i.e. the cable ends should not be connected back to the transformer. The glass blocks are connected with Scotchlok 804 type connectors, according to the manual attached to the connectors. While laying cables in the seam between the glass blocks you must not stretch them – they should lie freely. The connection should be carried out with power supply switched off. After connecting each glass block and before pouring mortar over them, the power supply has to be switched on in order to check if the connection has been carried out properly and if the glass block functions correctly (the glass block should shine). After everything has been checked and works correctly, the cables in the seam should be laid and the connectors placed between the corners of glass blocks.