Getting Started; Making Connections; Using Auxiliary Power - RC watt's up WU100 User Manual

Information Display
5

GETTING STARTED

Please be familiar with the contents of the SAFETY PRECAUTIONS section before
continuing.
5.1

Making Connections

Watt's Up is supplied without connectors so you can use whatever kind you prefer.
Always connect and disconnect power at the meter FIRST on whichever of the LOAD
or SOURCE sides that has the highest electrical inductance. This is usually at the
LOAD. Long wire runs, motors, generators, etc. can have considerable inductance.
If you attach connectors to the SOURCE and LOAD leads that mate with those you use on
your models it will be easier to do testing with your Watt's Up. However, it is strongly
recommended that you only use female connectors on batteries and other power sources to
prevent connectors and bare metal contacts from shorting together.
For example, with female (socket) connectors on your battery you will want male (plug)
connectors on the Watt's Up SOURCE leads and female connectors on the Watt's Up
LOAD leads. With this configuration, the Watt's Up can be inserted, like jumper cables,
between the battery and a load such as a ESC with Motor.
The user is responsible for selecting connectors rated to handle the current and voltage
expected in the user's application and to follow the instructions provided with the
connectors to ensure best results.
Only qualified individuals should assemble any high current connections.
The Red SOURCE wire goes to Positive (Plus +) battery or other device terminals and
black to Negative (Minus -).
Warning: Loose and intermittent connections can cause component damage!
5.2

Using Auxiliary Power

By connecting a receiver battery pack (of at least 4.0 V) or other power source to the 3-pin
connector on the SOURCE side, the Watt's Up can measure down to 0 V. This makes it
possible to measure the characteristics of a single battery cell.
The 3-pin connector's socket will accept a Futaba J type, JR or HiTec type servo plug
connector. A suitable connector with wires attached is available for purchase from our
website.
Pin 1 is Negative (0 Volts), pin 2 (middle pin) is Positive. Pin 1 is the pin farthest from the
Watt's Up SOURCE wires. Pin 3, on meter versions 2.1 and above, is for reset of
accumulated readings. See below for description of reset operation.
When using Auxiliary power, you may see small measurement values when the SOURCE
and LOAD leads have nothing connected or are shorted together. It is neither unusual nor a
problem for there to be small values displayed in this situation. This will not affect
performance when making real measurements.
The Watt's Up has been optimized to provide highest performance for real measurements
of connected power systems and loads, but with all leads unconnected may produce
erroneous readings. With real connections, accurate readings will be produced. Note that
shorting the SOURCE leads together and/or the LOAD leads together may show a very
small voltage (e.g. 0.01 Volts). These small "shorted lead" voltages are well within
specification and don't affect the accuracy of real measurements.
Caution: Never short leads for testing with a power source connected to either set of
leads!
"Watt's Up" & "Doc Wattson" Watt Meter and Power Analyzer User's Manual
11
RC Electronics, Inc.