To make the water system professional’s job just a little easier, Franklin Electric introduces a new troubleshooting tool for QD Control Boxes. QD, of course, is short for “Quick Disconnect”, and the QD Control Box offers the benefit of quickly and easily removing the components in the box.
For systems that use the QD Control Box, this new diagnostic tool, called the QD Service Box, allows easy measurement of motor voltage and current while the motor is operating.
Measuring the amount of current between the Control Box and the motor is important and helpful because it indicates how “hard” the motor is working. As a general rule, the motor current should never exceed Service Factor Max Amps (SFMA). If SFMA is exceeded, this is an indication that the motor is overloaded. This could be caused by several factors, including operating the system at open discharge, or on the far right side of the pump curve. If the current to the motor is much lower than expected, this indicates the motor is underloaded. Although this doesn’t always cause a problem for the motor, it may indicate a problem somewhere in the water system, such as a plugged intake or screen. Values for Service Factor Max Amps for all Franklin submersible motors can be found in the Franklin AIM Manual.
As you know, in the case of a 3-wire motor, there are 3 power leads from the Control Box to the motor (red, yellow, black) plus a green ground wire. When troubleshooting, the motor current should be measured in each motor lead. In some cases, the leads from the Control Box to the motor will be in conduit, or otherwise difficult to access. This is where the QD Service Box will come in handy.
With the QD Service Box in place, you can reconnect power and now easily measure current in all 3 motor leads. As mentioned above, correct values can be found in the Franklin AIM Manual. In addition, 2 jacks at the bottom of the QD Service Box accept voltmeter probes so that voltage can be measured while the motor is operating.
When measurements are complete, disconnect power before removing either the control box cover or the QD Service Box. Remove the QD Service Box and reattach the QD Control Box lid.
Contractors that have tested this product have had positive comments. It provides a handy method for thoroughly and accurately checking the motor’s vital signs.
The QD Service Box can be ordered from Franklin Electric’s website via a major credit card for $25 (plus shipping charges). The website address is http://www.franklin-electric.com
As always, if you have any questions, refer to Franklin Electric’s AIM Manual, call our Service Hotline at 800-348-2420, or email from the website.