Halides and Extension Cords

@tangster - I think you asked me what kind of ballast I have... I am looking at the pdf now and it just refers to it as "HQI ballast." It is a coralife Advanced series hang-on tank mount 150w HQI setup:
Oceanic Systems | Products | Aqualight Advanced Series - Hang-On Tank Mount

 

My favorite technology analogy is water/electricity.

pipe = wire
pressure = voltage
flow = current

For a given sized pipe you can only fit so much flow through at a given pressure. There's a trade off.

A large short pipe can handle a lot of flow at high pressure. Big pipe costs more.

A long skinny pipe takes much more pressure to match the flow of a larger pipe - till it bursts. Small pipe costs less.


In the case of wire, a given gauge will only push so much current at a given voltage. If the current demand goes up, the voltage will go down. As the voltage goes down the current goes up. All electronics find a balance, and all wire has a point of diminishing returns where eventually it will either melt or you'll pop the breaker.

So while at "rest" a line might have 115v available to it, when the device is turned on it might only get 112v. If you measure it at a point before that source you'll still see 115v. If you're an electrician you'll know how to add a draw to the line and measure it "under load" which is why you don't see it if you just plug into an outlet on the circuit.

to the OP:
The longer the cord the larger the gauge you'll need. Also, as stated, every connection will sap some power from your set up. Mechanical timers sap more than digital timers, not much... but if you're on the brink of popping fuses and having problems, it might help.

I also suggest you get a device called a "Kill-A-Watt" plug in meter. They're great tools for planning electrical systems as they will tell you the exact current/voltage draw of an appliance, the power factor, watts, everything. Then you can plan accordingly.

Never exceed 80% of the published rating of your breaker, i.e a 15 amp breaker should never have more than 12 amps of appliance on it. This gives you a large safety factor, and keeps you from adding enough current to the system that it drops the voltage.