Olympia Cremina Electrical Troubleshooting Guide
Olympia Cremina Troubleshooting Guide
The Olympia Cremina has a 1000 watt heating element which, in the US, uses standard 110 voltage. This translates to a machine which runs at a 9 amp current and has an element which mathematically computes to having a resistance of about 12 ohms.
Most Creminas do not have a polarized cord plug, but on a standard grounded wall outlets, the slot on the left is the neutral line (larger hole) and the slot on the right (smaller hole) is the hot line, assuming your outlet is wired correctly....this corresponds to the Cremina plug and cord, with the white wire being the neutral wire and the black the hot....some cords may have been changed but most have a 3 wire configuration, white-neutral, black- hot and yellow/green is the ground wire.
If you are having very mysterious behaviour with a new (to you) machine, you may want to begin your troubleshooting with your wall outlet.....the basic rule of thumb on a standard wall outlet box is that black is hot, white is neutral, and the copper wire is ground.....the mnemonic for wiring the leads to the screws on the side of the recepticle is "white is bright and black is brass". The white wire should be attached to the silver colored screw and the black to the brass, with the copper to the green screw on the box. The wall outlet is the point of departure to the machine and it must be properly wired for both safety and proper function of the machine....(mostly safety for the operator as it will work fine when wired backwards until you think it is OFF when it is actually just NOT ON but has electricity flowing and while resting your hand on the machine and touching the water faucet handle you will get the shock of your life)....so safety first....uniform electrical code exists for a reason!!!
If you are concerned about troubleshooting, you must be having some trouble or other. The electrical health of the machine can be determined by using an electrical multitester, logic, careful observation, and minimal basic tools.....a screwdriver will generally be all you need. A small inexpensive multitester will generally suffice and the most important function, for troubleshooint purposes, is as an OHM meter. The ohm is a measure of resistance in a circuit but for our purposes we use the ohm meter to test for continuity. A circuit is continuous when current flows and discontinuous when current does not flow....current will not flow through a broken wire, for example, so it is discontinuous, no continuity.....we will refer to positive continuity as C and no continuity as NC. When a switch is ON, it is closes, has continuity, and therefore C. An open switch is NC, etc. To use the multitester, set the OHM setting on the smallest value for the highest sensitivity and touch the two ends of the test probes together....depending on your tester, it will read either 1 or 0....this indicates Continuity. Our test meter reads 1 for NC and .4 for C (the meter is a bit old and out of calibration but the information is the same, it tests open and closed circuits).
The Cremina, and all other espresso machines for that matter, have 7 basic electrical components
- power cord
- wiring harness, consisting of the wires and terminal connectors
- main power switch
- pressurestat switch
- thermal safety switch
- heating element
- pilot light
First things first
Check the power cord by touching one probe to a plug prong, and the other to the wiring block screw in the frame of the machine.
If there is no wiring block, touch the probe at a metal part of the wire at the main switch. This is to test to see if the power cord is good. Test all 3 wires of the cord to make sure you are getting power to the machine. If you cannot find a metal wire to touch you may have to disconnect the wires at the power cord inside the machine to make sure the cord is good.
Once you have determined that the cord is C on all 3 wires check the wiring harness.
The wiring harness is the total of wires and connectors that connect all the conponents of the electrical system. Look at all the terminal connectors to see if they are burned or melted. A melted terminal cover means that the contacts are oxidized or dirty, causing the connector to heat and melt the plastic covering. On the Cremina all of the wires end in FEMALE spade terminals and all of the compenents have MALE spade terminals. The female is the one with the plastic cover.
To safely remove the female spade without damaging the componenet you may find it helpful to use a flat tip screwdriver as a small prying device. This will aid the initial movement of the connector, break it free, then it can be grasped, and pulled off with a wiggling motion.
If you have a melted terminal cover replace it with a new one by clipping off the old terminal and crimping on a new one with an electrical crimping tool....cut the wire close to the old connector as not to waste wire. Before connecting the new terminal, clean off the old one until it is shiny metal by use of sandpaper or steel wool, a dremel brush, or whatever, but get it clean so makes good contact, and so it does not melt again. The Cremina terminal covers are nothing special (no high temp or special material....just plain old plastic) so you can replace them with plain inexpensive plastic covered terminals. You can use high temp teflon covered terminals but they are quite expensive and will mask any oxidation problems you may have, as they will not melt until they reach 700 F.
Check the entire harness and all the terminal connections to make sure they are tight with no broken wires or unhooked terminals. Tug on the wire to make sure the connections are all solid. If you are replacing burned terminals do so one at a time and reconnect them as you go.
Now, the most important thing DRAW A WIRING DIAGRAM!!!! Use pencil and paper and write it all down, including the color of wire and if you have two wires the same color, mark the wire in some way to tell them all apart. DO NOT RELY ON A DIGITAL PHOTO. DO NOT RELY ON YOUR MEMORY. DRAW THE DIAGRAM AND YOU WILL NOT REGRET IT!!!! If your machine was working fine before your current troubles then you will replace the wires just as they were to begin with and if it was not working you will need this diagram to study and logic your way through just why it is not working, if all compnents check out OK..
Testing the Components
In each case, testing a component of the system is approached exactly the same way: unhook the wires from the component in question, set your multitester to OHMS and attach the leads of the tester to the male terminals of the component, and observe the result as follows.
Heating Element---Element tests good if you read an ohm reading of around 12-13 ohms. Any ohm reading at all is generally indicative of a good element. If you get a C reading then the element is shorted and must be replaced. If you get a NC reading the element is burned through, current is not flowing, and it must be replaced.
Pressurestat Switch-----The pstat switch defaults to C (closed) when the machine is off, or cold. It is simple to remove the pstat from the machine at the upper tube fitting, to remove the wires. The switch should be closed and give a C reading. The pstat spring can be manually compressed to assure that the switch will click to off (NC) position and back to ON (C).
Thermostatic Safety Switch-----Creminas have either manually resettable switch (small button in center) or an automatically resettable switch (no button, switch resets when it cools down 30 degrees). This switch should read C when cold and click over to NC when hot. You can heat the bottom carefully with a match or lighter or even on a fork over a burner on the kitchen range to assure yourself that it will both click off and back on when you push the button or wait for it to cool. You don't need a lot of heat to check the function.
Main Power Switch-----this is a double pole single throw switch (DPST) rated at 20 amps 125 volts....more than enough for a 9 amp machine. With the wires unhooked from the switch you should have NC in the off position and C in the on position, but only with one set of contacts....one side or the other. C on upper left and lower left or C on upper right and lower right. Anything else means the switch is shorted and should be replaced.
Pilot Light-----mostly a no brainer here. The pilot light is a short loop circuit that operates only when the current is passing through the element. If the small neon bulb burns out the element will still function but with no light. Generally if the pilot light does not work it either has a loose connection or is burned out.
General Tips and Observations
Many electrical issues can be solved with some good housekeeping of the wires and connectors. All melted or suspect terminals should be replaced and all contacts checked for oxidation as a matter of maintenance. Do not use or tolerate any black electrical tape in your machine....this hides issues that are easily solved. If you need to lengthen a wire use a proper crimp connector or solder and shrink tube....do a good job and do it once.
Do not go into denial over some electrical issue....your meter will not lie. If it says the component is bad it it bad and if it is good alls the better.
Make sure your ground connection is good and solid....this one wire can make a large diffenece in the saafety of the machine.
If replacing wire, use 14 or 16 gauge wire, preferabley teflon coated as it will last forever. We have not mentioned wire colors in our electrical guide.....from seeing machines from the 1970' to the 1990's we have observed no standard wire color schemes....better to go by a wiring diagram anyway.
Of the few dozen Creminas we have repaired most show some electrical repair or modification in the past, most commonly the thermal safety switch has been changed. Almost all have at least one melted connector some have all of them melted. We have not seen a burned out pilot light but many are quite dim. Mushy switches still work but sometimes a mushy feeling switch will throw a small spark when turning on or off....not a good thing. The old style long switch cannot be gotten for love nor money but can be replaced with a plastic bodied switch (after enlarging the mounting hole with a file....not an ideal solution but a workable one. All the components can be renewed either with OEM parts or reasonable alternatives so if you find a deficient electrical part in your system do not despair....better to fix it than bridge around it. Keep safe so you and your machine will have many happy pulls!!!!!