Stealth PID install w/ alarm lights

I got this idea from Murph's Siliva PID Page, but I didn't use a neon
light. I wanted to, but I didn't want to have to buy a transformer,
rectifier, power supply or whatever to convert 120VAC to 12VDC (I
found some really cool after market PC and car lighting to install if
anyone is interesting in doing a DC alarm).

Here are pics of the install (yes, I gave her a tattoo while doing

It is very simple, costs under $12.00, uses the existing Rancilio
badge holes and requires only two different parts:

- (2) Blue Sea Systems 11/64" 120V LED w/ leads
- specs:
- best price shipped: - search by part
number from manufacturers web site.

- (1) piece of 2-3" wire rated for 120V
- Solid wire is probably better for this application
- You might need a longer wire depending on your pid
- You could buy two spades [about $.12 each] to crimp on the ends
of the wire. It would probably make things a little easier.

Your PID will need to be AC powered and have an AC alarm/output relay
in order do to this in the way I am describing. The Love 32B output 2
relay is rated at 250VAC and 5A, so 120V is no problem and the draw is
no more than 1 mA with two of these 120V LEDs.

[[__--==<<It's not my fault if you kill yourself doing this.>>==--__]]

1. Power off the machine and unplug it.

2. The holes from the Rancilio badge are 4mm. The mounting hole size
required for this LED is 11/64" or 4.36mm. You could try to sand down
the LED, but I chose to enlarge the badge holes by 0.36mm or 0.014".
I used a dremel tool with a conical filing bit attached to it. I
pulsed the dremel tool using low speed and high pressure to enlarge
the holes. This took about as long as the rest of the steps
combined. I didn't feel that any lubricant was necessary. By using
short pulses and high pressure the steel never got too hot to touch.
Keep test fitting the LED and filing until you can easily push the LED
in the hole until the little ribs on the side of the light touch the

3. Push the LED all the way in once the ribbing hits the metal. You
might need to use a tool to help. The chuck wrench for the Dremel
tool was perfect because the hole in the middle was slightly larger
than the LED, but not as big as the LED socket. I placed LED bulb in
the hole on the wrench and pushed the wrench until it seated the LED
up against the case. This did put little scratches on the bulb
socket, but it is hardly noticeable (unlike the big scratch I made on
the case with the Dremel tool).

4. Disconnect both of the 120V power wires going into the pid.

5. Strip the new wire about 1/4" on each side and bend it enough to
hook around the screw terminals on the back of pid.

6. Piggyback the new wire onto the power terminal with one of the
original power wires and tighten so that both wires are securely
attached. No bare wire should be exposed outside of the terminal.
Give a tug on both wires. It could be very bad if one of those wires
became disconnected while the power is on.

7. Connect the other end of the new wire to the relay (I attached
mine to the + side, but I don't think it matters).

8. Twist the bare end of one wire from each LED together, bend the
bare end into a hook and attach to the other relay terminal.

9. Twist the remaining wire from each LED together and piggyback it
onto the remaining power wire and tighten well (like in step 4). The
connections should look like this. Both original power wires are
connected to their original location. A small wire is patched from
one of the power terminals to the relay terminal on the back of the
pid. The two LEDs leads are twisted together with one wire from each
LED connected to the other side of the relay (not the hot side) and
the other LED wires are connected to the other power terminal (not the
terminal with the piggyback wire attached to it).

10. Turn on the machine and configure your alarm. The reverse
deviation upper and lower limit alarm type will allow you to specify
when you want the alarm to come on in relation to the set value. I
have mine set for +0.1 / -0.1. So the light comes on when the
temperature reading is 227.4 through 227.6. The +/- deviation doesn't
need to be the same value (at least on my pid). If you change your
set value, the deviation remains the same, so their is no need to
adjust the alarm when you change your set value.

I start the shot after the light has been on for a few seconds. If I
just pulled a shot, it usually, but not always, overshoots the first
time so I ignore the first light. After that it is good to go.

I thought heat might be an issue. I measured 130F in the case where
the pid is located. It jumped to 140F after steaming the boiler dry
(to find the extreme) then cooled down to 130F. It wasn't above 130F
long enough for me to worry about it and this pid is rated for 130F
operating environment. I might wrap it in reflective thermal
insulation, but I am open to suggestions.