LTH Electronics BPD17 - Fault Finding

Faults
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BPD17 pH / Redox Monitor
Operating Guide
Fault Finding
NOTE: THERE ARE NO USER SERVICEABLE PARTS INSIDE THE UNIT
The BPD17 has been designed to include a wide range of self-diagnostic test, some of which are
performed at switch on, and some on a continuous basis. This guide aims to provide a route to
diagnosing and correcting any faults that may occur during normal operation. The table shown
previously in this section gives a list that the BPD17 generates, along with their probable causes. If
after these checks the fault has not been cleared contact LTH. Please have as much of the following
information available as possible in any communication with LTH, to enable quick diagnosis and
correction of the problem.
 Serial number of the instrument.
 The approximate date of purchase.
 Details of the program settings and application.
 Electrical environment and supply details.
 Circumstances under which the fault occurred.
 The nature of the fault or faults.
 Any error messages that are displayed.
 The sensor type, cable length and type.
 Current output configuration.
 Relay connection configuration.
 Digital Input Configuration.
It is often worthwhile to check the measurement by an independent method, for example using a
handheld meter.
The Instrument Appears Dead
Check that power is available to the unit. Using a voltmeter, set to AC or DC, check the power supply
voltage at the connector. The design of the BGD17 allows the unit to accept from 90 to 265V AC, an
alternative option allows operation from 12 to 30V DC, check the connection label for voltage
specification. Check that the power cable is securely and correctly attached. There are no user
serviceable fuses fitted within this unit.
The Access Code Does Not Work
It is probable that the access code has either been changed or the operator does not recall the code
correctly. Contact LTH or your local distributor should this problem arise.
The Sensor Reading Is Constantly Over-range or Under-range
 Ensure that the sensor and temperature input is correctly connected (see Installation and Choice of
pH / Redox Electrodes page 20) and that the sensor is not faulty or damaged.
 If the units are set to pH, check the temperature compensation state (see Channel Setup Section
page 30). If the compensation is set to “Manual” check that the fixed temperature is at the correct
level. If the compensation is “PT1000 or PT100” check that the temperature reading on the main
display is correct.