Electric Engines are power converters introduced by the Transformers Mod. They run off IndustrialCraft 's EU Power and convert this into Buildcraft 's MJ power. There are a total of four types of engine added by the Transformers mod, which were added to the Technic Pack to replace the removed Electrical Engine from the Forestry mod.
However, in the current build of Technic there seems to be a bug. Fast and Adjustable Electric Engines attached directly to a refinery don't put all their power in the refinery, when putting a wooden (HV) conductive pipe and a stone conductive pipe between them, this problem can be solved. The same goes for a quarry. Be very aware of this, since you can lose a lot of time and energy (the engines seem to consume the right amount of EU, but don't put the expected amount of MJ out.
Like other engines a redstone signal must be applied to activate this engine.
Slow Electric Engine (LV)Edit
The Slow Electric Engine (ID 2367) produces 1 MJ/t and uses 2.5 EU/t per default - this is equivalent to the energy output of a Steam Engine. It accepts up to 32 EU/t (LV) before exploding.
Regular Electric Engine (MV)Edit
The Regular Electric Engine (ID 2367:1) produces 5 MJ/t and uses 12.5 EU/t per default - 1 MJ/t less than a combustion engine running on fuel. It accepts up to 128 EU/t (MV) before exploding.
Fast Electric Engine (HV)Edit
The Fast Electric Engine (ID 2367:2) produces 10 MJ/t and uses 25 EU/t per default - this is equivalent to two combustion engines burning fuel, the exact amount a refinery/quarry/pump needs to run at maximum speed. It accepts up to 512 EU/t (HV) before exploding.
Adjustable Electric Engine (EV)Edit
This engine is adjustable, which means that you can adjust the amount of MJ/t it will produce and thus the EU/t it will use. It accepts up to 2048 EU/t (Extreme Voltage) before exploding.
It has a GUI where you can set the amount of energy it will produce.
However, due to the ability to adjust this engine, normal wooden conductive pipes cannot handle this engine at high capacity, so a new pipe named the "HV Wooden Conductive Pipe " has been created to handle this engine at faster speeds.
This is the GUI for adjusting the engine: