Handyman Motor Capacitor Meter PART NO

Transcription

1 Handyman Motor Capacitor Meter PART NO To test a motor-run capacitor in the field with no capacitance meter at hand, you had to hook up the capacitor through an extension cable to a 120V wall outlet, measure its Amp draw, actual volts and run a calculation using the following formula: I MicroFarads = x 2652 V With this kit, you still need to hook up the capacitor to a 120V 60Hz wall outlet. Using a clamp type Amp meter you should get a reading in Amps that would be equivalent to its capacitance in micro Farads. For example, a 10uF capacitor would cause the Amp meter to show approximately 10 Amps, a 50uF capacitor would cause the meter to show about 50 Amps, etc. The capacitance range goes from about 1uF to 100uF which corresponds to most motor-run capacitors found in home appliances. CAUTION: The operation of this kit involves 120V line voltage, even though precautions have been taken to reduce the risk of electrical shocks, the user must be extremely careful to avoid contact with line voltage during testing or charged capacitors right after pulling the plug. Line voltage is DANGEROUS and can cause injuries and/or death. Do all the connections to the capacitor-under-test BEFORE PLUGGING IN this kit to a wall outlet. Take Amp readings and once you are done, unplug the kit without touching the plug's terminals and WAIT AT LEAST 1 (ONE) MINUTE to let capacitor-under-test discharge before disconnecting the capacitor from the kit. Time Required: 1 hour depending on experience Experience Level: Intermediate Required tools and parts: Tools: Soldering iron Crimping tool for quick disconnect terminals Wire cutter/stripper Long nose pliers Knife or box cutter Lighter Supplies: Solder Black Electric Tape Scotch Tape Bill of Materials: Qty Jameco SKU Component Name Power Cord 6' AWG 18/2 SPT2 Black Pigtail Wire Hook-up Solid 22 AWG Black 25 Feet Fuseholder In-Line 22AWG 3"x 1.25"x.25" Fuse Fuse AGC Fast Acting 10A 250V.25x1.25" Resistor Carbon Film 100k Ohm 1/2 Watt 5% (In Bags of 10 and 100)

2 Inch (5mm) Black Polyolefin Heat Shrink Tubing - 10 Feet AWG Insulated Faston Terminal Step 1 - Verify kit is complete Make sure you have the following parts: Qty. P/N: Description Power Cord 6' AWG 18/2 Black pigtail Solid Hook-up wire 25' Black Standard inline fuse holder 1-1/4" x 1/4" 22 AWG K 1/2W 5% Resistor (bag of 10) Polyolefin Flexible round heat shrink tubing 10 feet /4"x 1/4"Standard fast acting fuse 10A AWG Insulated Faston Terminal (bag of 10) Step 2 - Insulate Discharge Resistor Take one 100K 1/2W 5% resistor and cut approximately 1-1/8" off heat shrink tubing. Insert the resistor through the heat shrink tubing and apply heat to insulate the body of the resistor and part of the leads leaving the ends of the leads uninsulated as shown in picture.

3 Step 3 - Prepare Power Cord pigtails Using a wire stripper, remove enough insulation so pigtails are left with about 1"of copper exposed. Step 4 - Add two pieces of 1"each of heat shrink tubing. Cut two pieces of 1" each of heat shrink tubing and add them to the pigtails as shown in the picture. Step 5 - Install Discharge Resistor Take one end of resistor previously insulated in step 2 and wrap it around one end of power cord. Using long nose pliers, make sure no part of the resistor's lead is sticking out. Apply flux to this lead and solder properly. Spread apart both pigtails so you can solder in the other end of discharge resistor on the other pigtail. Again, make sure the resistor's lead is not sticking out either. Step 6 - Insulate Pigtails Cut two pieces of about 5/8" off heat shrink tubing to insulate the connections done in previous step. Slide in heat shrink tubing on one pigtail covering both the insulated resistor lead and the previously insulated cord end so there is about 1/4" of exposed copper left at Power Cord end. Do the same on the other lead of Power Cord. Apply heat so Power Cord's ends look like the picture.

4 Step 7 - Install Quick disconnect terminals Slide in one of 1/4" pigtails into one quick disconnect terminals making sure no metal parts from the cord-resistor end are exposed. Once you make sure everything's right, crimp terminal in place. Do the same with the other 1/4" pigtail. Step 8 - Make metering coil Wrap 22 turns of the hook-up wire around a cylindrical object with about 2" in diameter. To make things easier before start, fix one end of the wire with scotch tape and wrap around the wire. The coil you get must not be tight as long as you get 22 turns. Slide the coil out and keep the coil shape in place with electrical tape. These 22 turns will multiply motor-run capacitor actual current so you get the right current reading in Amps which would correspond to actual capacitance in Microfarads when line voltage is 120V. The reading will vary about +/- 4% when line voltage ranges from 115V to 125V. If your line voltage is constant at either end, you can experiment adding or subtracting one turn to this coil. Example: 21 turns with 125V or 23 turns with 115V. Step 9 - Identify "hot" pigtail in power cord Using a multi meter in continuity mode, have one test probe touch the narrower terminal of plug (the hot lead), and with the other test probe, test the quick disconnect terminals for continuity. Once you identify the "hot" conductor, mark it for next step.

5 Step 10 - Cut identified conductor in previous step Using a knife or a box cutter, separate the conductors of the power cord at about one half or one third of its length from quick disconnect terminals. Separate both conductors for a length of at least 6". Cut the conductor corresponding to the hot leg with a wire cutter. Step 11 - Install in-line fuse holder & current sensor Strip off about 1" of insulation from the ends of both, the in-line fuse holder and current sensing coil. Cut one 1" off of heat shrink tubing and slide one end of the inline fuse holder leads. Twist one end of current sensing coil leads around the end lead of in-line fuse making sure that the twisted wires do not exceed in thickness of the in-line fuse holder lead insulation. Carefully apply solder to this joint so no heat reaches the heat shrink tubing. Slide heat shrink tubing to cover the joint and apply heat with a lighter to shrink the tubing in place. Using the just soldered in-line fuse holder and current sensing coil as a reference, cut off a section of the hot leg conductor in the power cord. On the plug side of power cord, strip about 1" off the end of this hot leg conductor insulation, cut off one 1.5" piece of heat shrink tubing and slide this conductor through it as far away as possible from the copper end. Twist the free end of in-line fuse holder along with this power cord end making sure that the thickness of both twisted wires does not exceed the power cord's conductor insulation. Apply solder to the joint and when cold, slide the piece of heat shrink tubing over the joint. Apply heat to shrink tubing in place covering the joint. Do the same on the remaining end of current sensing coil and quick disconnect terminals end of power cord. Make sure all joints are properly insulated for safety. Step 12 - Tape fuse holder and coil to power cord Take the 10A Standard fuse and put it into in-line fuse holder. The fuse holder is opened by twisting action and closed by twisting in the opposite direction until locked in place. Do a continuity test between each quick disconnect terminal and its corresponding plug's lead. Make sure that there is no short circuit between quick disconnect terminals. This fuse is meant to blow in case quick disconnect terminals get accidentally shorted together or a shorted capacitor gets unknowingly tested. Now, put the in-line fuse holder and current sensing coil pair next to the other conductor of power cord and tie them together with electric tape (or plastic ties if available) for a nicer appearance.

6 Step 13 - Final Testing DO NOT PLUG IN HANDYMAN CAP METER YET! Insert your handyman cap meter quick disconnect terminals on capacitor-under-test terminal tabs making sure not to touch them in case capacitor still holds a charge. If the capacitor is charged, it will discharge through the handyman cap meter's discharge resistor. Clamp your Amp meter around the handyman cap meter's current sensing coil. Adjust the scale (if not auto-range) using the capacitor label microfarad rating as a reference, i.e. If 50uF, then adjust the scale so your meter reads 50A. Once you are sure everything's OK plug in the handyman cap meter to a good known wall outlet. If the capacitor is OK, the Amp reading should be approximately the same as the nameplate microfarad. Do not leave your handyman cap meter unattended for too long, once you've taken your reading unplug the handyman cap meter from the wall outlet and let the capacitor-under-test discharge for one minute. Remove capacitor and if you need to test another one, repeat the above procedure. * * * WARNING * * * Due to the fact that handyman cap meter's current sensing coil's wire ampacity is 7 amps and in order to be on the safe side, YOU MUST NOT test motor-run capacitors bigger than 100uF with this handyman cap meter. A 100uF motor-run capacitor draws approximately 4.5A at 120V. Leaving a 100uF capacitor energized at 120V for too long will cause current sensing coil to get warm to the touch.