I'd like to have a 220 line run to this panel, but I'm not sure if I have enough room. It looks like there are two empty spots, but there is a red tab connected to the main line that appears to block the two adjacent slots.

 

No you don't have the space unless the panel will take tandem breakers. That is a back fed main lug panel so the main breaker has a retainer so the breaker can't be mistakenly removed. How old is that panel? On 3 conductor feeder to a subpanel the neutral and ground should be bonded, yours is not. Current code requires 4 conductor which has an equipment ground back to the main panel with the neutrals and grounds isolated in the subpanel.

 

There's an ink stamp inside dated November 2004. How hard is it to bind the neutral and ground? Is particularly dangerous not to have then bound?

 

It helps clear faults better. Just having the ground to earth is not the best ground for clearing faults. The large solid bare copper wire from the ground bar should be going to ground rods driven in to the earth and mainly serve for lighting strikes. You can add a bonding strap from the neutral bar to the case or add a piece #6 solid copper wire between the neutral bar and ground bar. With the 3 wire system, faults are cleared via the bonded neutral.

 

I think this is a tandem panel board. The model number is Siemens G1224L1125, which is 12 spaces 24 circuits. http://i.imgur.com/iNXYg2Z.jpg

It says that it's 125A max, which seems like that has been surpassed judging by the amps written on all the circuit breakers. Do you guys think I can get a 240v 30amp tandem breaker to work in this panel in addition to all the other breakers already there? I'm hoping to get an electric water heater without getting a new panel.

 

You can't judge how the panel is loaded by the size of the breakers. You have to add up the loads to see what you come up with.

It is possible to have every receptacle in the house on it's own breaker. Then you'd have hundreds of amps of breakers in place but minimal load on each breaker.

That panel looks to be minimally loaded so a 2P30A breaker for a water heater should be fine.

In the picture I highlighted a screw. Is that screw green ? That looks to be a neutral bonding screw. It would connect the neutral to the panel cabinet.

 

Look at the breaker outlined in red. Is the one below it the same rating ?
If it is you may be able to put a twin breaker where the red box is and your two pole breaker where the blue box is.

 

Here is a higher quality picture of the panel

They are not the same, the red is 15A blue is 20A.

 

No problem.... you could use a breaker like in the link....
Siemens 15/20 Amp Tandem Single-Pole Type QT Circuit Breaker-Q1520 - The Home Depot

That panel is listed as 12 space/24 circuit which means you can use a tandem breaker in any or every location.

And that appears to be your neutral bonding screw.

 

This is very good news... thank you.

Also, I assume that is an empty slot below the blue square you drew, is it better not to have a 220v 30amp tandem breaker when it could just be a regular breaker or does it not matter at all?

 

A 240v breaker is a two pole breaker and needs to connect to both busses. That means it needs to be in two full size spaces.

A tandem breaker connects both circuits to the same buss. That means each 1/2 of the breaker can only be used for a 120v circuit.

That appears to be an empty slot unless I'm missing something.

 

Side note:

Your panel is back feeding a 90 amp breaker. That makes me believe it is a sub panel as minimum service for a home is 100 amps. Is this a sub panel? If so, there are some other changes to be made.

 

The panel is on its own meter, so if my understanding of what a sub panel does is correct then I don't think it's a sub panel.

 

Is there a main breaker out by the meter?

 

It looks like it's only the two meters outside the house, it's a house with an attic apartment. Picture of the meters here. The meter on the left is for the attic apartment that I am concerned about.

 

That's.....Interesting. Not the kind of setup I see around here. Your panel appears to be a main panel. Carry on!

FYI - Most states/cities do not allow anybody but a homeowner, or contractor, to do electrical work.

 

That large copper wire from the ground rod is supposed to be terminated on the neutral bus and not on the ground bar. The way it is currently terminated on the ground bar is a code violation. The purpose is to ground the neutral. The neutral bus is then bonded to the panel box.

 

The neutral bus is bonded to the can with the large green screw.

 

So another question regarding this panel... It appears that I have a MWBC (multi-wire branch circuit) on the two breakers in the bottom right corner of the panel. What would I have to do to be able to have GFCI outlets on both circuits? I know there are some issues with doing this and I'm getting conflicting information on how to do it properly. I intend to have a GFCI outlet and 2 daisy chained outlets with a switch for a garbage disposal on the one circuit and the kitchen lights with another GFCI outlet and 1 daisy chained outlet on the other circuit.

Is this possible with a MWBC or should I just install a double pole GFCI breaker or get rid of the 12/3 MWBC and just run another 12/2 instead?

 

Installing a 2 pole GFCI breaker if they are the same amp rating would be the easiest option. The other option would be to install GFCI receptacles at each location you want a GFCI. The wires in the boxes need to be spliced together and the devices connected to the wires with pigtails.

 

So if I understand you correctly, I can't daisy chain regular receptacles to a GFCI receptacle with a MWBC?

 

You can not use the LINE and LOAD terminals of the GFCI receptacle on a MWBC because the neutral is shared. The circuit is still daisy chained with the cable going from box to box, to box, just each box will need to have its own GFCI receptacle.