Page 8 of 23 Elecsys Corporation, Olathe, KS 66061 P/N 81-0022-00 Rev J 03-2020
Basic Rectifier Monitoring + Interruption (rectifier output voltage, rectifier current, AC
detection, and GPS synchronized interruption)
Step 1 –Connect input power
1. Connecting to rectifier AC power
Assure the front panel power switch is in the “Off” position. The Watchdog Scout is designed to
operate on low-voltage AC or DC power. For AC power, source a stable voltage from the
rectifier in the 12VAC to 25VAC (50/60 Hz) range using a UL Certified step-down transformer
(recommended), or by connecting to the rectifier taps (provides less power isolation and
increases risk of damage from voltage surges). Connect the red and black wires from the
power input cable to the transformer output terminals or to the selected taps using terminal
connectors appropriate to the site.
NOTE: DO NOT CONNECT THE WATCHDOG SCOUT DIRECTLY TO HIGH
VOLTAGE AC POWER AS THAT WILL DAMAGE OR DESTROY THE UNIT!
2. TEG or Solar Generator DC Power (if only DC is available)
At TEG and Solar sites, the input power to the Watchdog Scout will be DC
supplied by the generator or storage batteries. Input power in the range of
10VDC to 35VDC is required for operation. To connect the Watchdog Scout
system to a DC external power source, connect the red power cable lead to
the positive terminal at the power supply and the black lead to the negative
terminal. For these applications a DC to DC converter is recommended in
order to supply stable, isolated power. Elecsys offers 2 DC to DC power
options (listed in the “Parts and Accessories” section on page 16).
Step 2 –Terminate the measurement input cable harness leads to the proper
points
The factory configuration of the Scout is set to monitor rectifier voltage, rectifier current,
and rectifier input power (AC present/not present). If this is the application desired,
connect the input cable harness wires as shown below:
Wire Color Channel Connects to
Red Channel 1+ Rectifier voltage output + terminal
Black Channel 1 - Rectifier voltage output –terminal
White Channel 2 + Positive terminal on the shunt
Green Channel 2 - Negative terminal on the shunt
Orange AC Probe + “Red” lead from the AC Probe
Blue AC Probe - “Black” lead from the AC Probe
If additional channels are needed, the following leads are used:
Wire Color Channel
Pink Channel 3 +
Tan Channel 3 –
Purple Channel 4 +
Brown Channel 4 –
Note: If channels 3 and/or 4, or the digital input channels, are to be used, or if the
channel configuration required is different than the factory default settings, the
channels will require activation and/or configuration. Configuration using the
front panel is addressed in Section 5 of this manual (beginning on page 10).
Common applications for the additional analog channels:
Pipe to Soil potential readings (Channel 3 provides On/Off potential readings
using the interruption relay).
Additional “negatives” where multiple pipelines are connected to the rectifier
