A transformer upgrade can be used to upgrade a machine's power input rate or tier. Place one or two transformer upgrades into the four right-most slots to upgrade a machine.
One upgrade enables a tier 1 machine to receive 128EU/t. Two upgrades enables it to receive 512EU/t and three for More than 512 EU.
Important: Make sure to put the transformer upgrade into the machine before applying power. Temporarily removing the wiring while setting up your machines is a good way to do this.