Fluke 1738 Power Logger Setup Checklist | Common Mistakes

Fluke 1738 Power Logger Setup Checklist: Avoid Common Mistakes Before Leaving Site

Setting up a power logger may seem straightforward, but small mistakes during installation can affect the accuracy of your results.

Incorrect current probe placement, unsuitable logging intervals or simply forgetting to start the recording session can leave you with incomplete data or, in some cases, no recorded data at all.

Before starting an energy study, load monitoring project or electrical investigation with the Fluke 1738 Power Logger, it is worth taking a few minutes to check the setup.

This checklist covers some of the most common Fluke 1738 setup mistakes and explains how to avoid them.

Why Correct Power Logger Setup Matter

The Fluke 1738 Power Logger is commonly used by electricians, maintenance teams and energy professionals for:

• Energy audits
• Load studies
• Demand monitoring
• Equipment performance checks
• Electrical system analysis

The data collected during a logging session is only as reliable as the setup behind it.

A correctly installed power logger provides a clearer picture of how equipment is operating, when energy is being consumed and where potential improvements can be made.

Common Issue #1: Choosing the Wrong Current Probe

The Fluke 1738 is supplied with flexible current probes that are designed to make installation easier, especially in crowded switchboards or around large conductors.

However, selecting the right current probe for the application is important.

Using a high-current probe on a smaller load may not provide the measurement range or resolution required to capture accurate results.

Common current probes used with the Fluke 1738 include:

• Fluke i5sPQ3 AC Current Clamps, 5A (3 x i5S per set) - TechRentals Australia only. 
• Fluke i40S-EL 3x40A CTs for secondary msmt 1777 or 1738
  
• i17xx-flex 1500 - (included in accessory list)
• i17xx-flex 6000 - (included in accessory list)

The Fluke 1738 can automatically recognise compatible probes and apply the correct scaling, but the probe still needs to match the expected current range of the circuit being measured.

Signs You May Have Selected the Wrong Probe

• Current readings appear lower than expected
• Small changes in load are difficult to identify
• Measurements do not match expected equipment operation

Common Issue #2: Incorrect Current Probe Installation

Correct probe selection is only part of the setup process. How the current probes are installed can also affect the quality of the recorded data.

Some common installation mistakes include:

• Clamping around more than one conductor
• Installing current probes in the wrong direction
• Connecting current probes to the wrong phases
• Not fully closing clamp jaws
• Incorrectly closing flexible probes

Each current probe should be installed around a single conductor only. Placing a probe around both active and neutral conductors can cause the magnetic fields to cancel, resulting in incorrect current readings.

The arrow on the current probe should also point towards the load. Installing probes backwards can result in negative power readings and incorrect power direction information.

Before leaving site, use the Fluke 1738 Verify Connection function to confirm:

• Phase rotation
• Phase mapping
• Current probe polarity

Common Issue #3: Selecting the Wrong Logging Interval

The logging interval determines how often the Fluke 1738 records average values during a monitoring session.

The correct interval depends on what you are trying to measure.

A shorter logging interval can be useful when monitoring:

• Equipment operating cycles
• Changing production loads
• Frequent load variations

A longer interval may be more suitable for:

• Extended energy studies
• General load monitoring
• Understanding overall consumption patterns

Choosing an interval that is too short can use memory faster, while an interval that is too long may miss important changes in equipment operation.

Before starting a logging session, check the available memory and confirm the selected recording duration will fit.

Common Issue #4: Forgetting to Start the Logging Session

One of the most common mistakes with the Fluke 1738 is forgetting to press Start Logging before leaving site.

The logger can display live voltage, current and power measurements without recording any data.

Seeing readings on the screen does not mean the logging session is active.

Before leaving the site, always confirm that:

• The logging session has been started
• The recording progress is visible
• The correct start time and duration are selected
• The averaging interval is correct

The Fluke 1738 power LED also provides a quick indication:

• Flashing green: Connected to external power and logging
• Steady green: Connected to external power but not logging
• Flashing yellow: Running on battery and logging
• Steady yellow: Running on battery but not logging

At TechRentals, this has been one of the most common issues identified with power logger rentals, which is why reminder labels have been added to Fluke 1738 units to help prevent missed logging sessions.

Common Issue #5: Using Battery Power for Long-Term Monitoring

The Fluke 1738 includes an internal battery, but it is designed for short-term backup rather than continuous operation during long monitoring periods.

For multi-day energy studies, the logger should be powered from an external supply wherever possible.

If the logger loses external power and the battery runs out, data collection will stop.

Before leaving site, confirm:

• The logger is connected to external power
• The logging session is active
• Battery status is checked
• The recording duration matches the project requirements

The Importance of a Power Logger Setup Checklist

A successful energy study depends on collecting accurate data over the required monitoring period.

Taking a few minutes before leaving site can help avoid common problems such as:

• Missing data
• Incorrect readings
• Repeat site visits
• Delayed reporting

A simple setup checklist ensures the Fluke 1738 is configured correctly and ready to capture the information you need.

Recommended Equipment

The Fluke 1738 Power Logger is designed for energy monitoring, load studies and electrical system analysis. It records voltage, current, power, energy consumption and harmonic trends to help identify how electrical systems are operating over time.

Using Fluke Energy Analyze Plus software, collected data can be reviewed, analysed and turned into reports to support energy audits, maintenance decisions and efficiency improvements.