8 port relay question

Other Hardware General Electronics
1

Hi,

I've got a SainSmart 8 port relay all wired up (tested to) thing is the hot goes from one terminal to other on relay board and some guy has used 14 gauge wire to input (normally connected) then output to next normally connected (so 2x14 gauge wires in one terminal) I'm not sure how he made the two wires fit in one terminal and trying to get 8 wires and another one from a power cord just seems wrong. Besides an electrical block any suggestions for connecting 9 wires of that gauge?

This is what I've made and step 6 http://www.instructables.com/id/Arduilay/?ALLSTEPS is what I'm wondering about.

2

Connecting each one to the next requires two wires in the hole. Unless the wires are too thick to fit, that doesn't seem unreasonable to me.

The whole project seems slightly dangerous, but that particular aspect doesn't stand out.

3

Although I'm looking for a solution to the power issues I have, I am also going to have this under a saltwater tank, so if anything stands out as dangerous please let me know. I actually have 2 Ethernet plugs controlling the relays (one for the 2 power cords and one for the 8 relays) Those Ethernet cords will go to the case that holds the Arduino.

4

http://farm4.staticflickr.com/3771/11318149454_e30165de10_m.jpg
http://farm4.staticflickr.com/3806/11318149994_eebc4c15bf_b.jpg
Here's some pictures. No way to put two wires (that I can find) into one hole.

5

The photos are not available?

Anyway, just a few comments on your project:

What is the total load going to be?
What is your voltage? 110v or 240v?

When you say you have 2 Ethernet cords for the power and relays, I presume (hope) that these are for the +5v and GND for the coils rather than for the high voltage supplies?

For the high voltage live side wires, rather than daisy chaining them you'd be better off using some sort of bus bar rated to the total max current + a safety margin. His original design seems dangerous and I think that his comments in step 10, after the photos, suggest he didn't keep this arrangement.

You can also see in this photo the upgrade to 14g wires and the splitting of each relay power wire to its own lead (versus the "staples" series used before).

For the bus bar, you could fabricate this yourself using 40A+ terminal blocks with heavy gauge "staples" of wire connecting each terminal block with it's neighbours on one end, and the input and all outputs on the other end. However, if you're going to be placing this where it may get wet, that's probably not the best idea either.

6

Thanks for the input. Notice how he has the Arduino in the bottom of the case I'm not going to have the Arduino in the case just Ethernet cables to connect the relays to the Arduino. The hot cable going in to the relays (110V) is a indoor/outdoor extension cord that has been cut and attached with spade terminals. I'd need to check but I think I use 14guage wires or larger for any connection (besides Ethernet wire for +5 relay control) I'm thinking I'm going to use a bar to connect the hot (110v) wires. I got a response on the Instructables website were It was said that the person initially making the device connected all the wires to the fuse. Thing is it really doesn't say how the connection was made. So that is the challenge I have.