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Safety Features - Protector Systems

Electric immersion heater coils and heater tube require that the portion that contains the heating elements be submerged in solution at all times.  Failure to do so will cause damage to the heater and may lead to tank damage.  The use of the 'Protector System' to monitor the temperature of the heating element is a safety device that is extremely important to understand when using electric immersion heaters.  The following Protector Systems are designed to monitor the temperature of the heating element and prevent the heater from excessive temperatures.  The use a liquid level controller is required from a safety standpoint.  The use of a temperature controller does not exclude the need for the Protector System.
Warning - Electric immersion heaters will ignite many plastic tanks such as polypropylene and polyethylene and subject personnel to shock hazard if not properly installed and maintained.
All heaters must be equipped with a thermal over temperature device such as a Protector I, II, or III, and tank MUST have a liquid level control to reduce the potential of fire.  It is the customer's responsibility to purchase thermal and level control protection.
Protector I - This over temperature control systems uses a heat sensitive fuse to detect overheating conditions.  The fuse is placed inside a thermowell, positioned in contact with the heater sheath, will cut power to the heater in the event of a low liquid level.  The fuse must be replaced after the shut off condition. Temperature ranges for fuses are selected by the expected temperature.  See Below.  Note:  PI fuses will require the use of a relay type controller if the heater load is greater that 15 amps.

Protector II and III - This fuse performs the save function to shut the heater off -- however offers a re-settable fuse and audible alarm within the controller.   The controller is supplied with the optional Protector II (or III) system, will include the alarm, cutoff circuits and reset button.  Do not wire PII or PIII directly to power or heater load - wiring diagrams are available upon request.

Note:  Most heaters are supplied with thermal overload protection - please advise desired solution temperature for correct sizing of protection fuse.

Protector System - Heater Construction Model of Fuse    Temperature Range Details
PI - All metal heaters over the side and thermowell. PI - to 180 oF (white # 3936)
PI-M 180 to 230 oF ( blue # 2924)
PI-H 230 to 300 oF (red # 3714)
PI - All metal L shaped heaters. PLI - to 180 oF (white # 3710)
PLI-M 180 to 230 oF ( blue # 3712)
PLI-H 230 to 300 oF (red # 3713)
PI - Quartz heater PQI - to 180 oF (white # 3936)
PQI-M 180 to 230 oF ( blue # 2924)
PI - PTFE over the side PTI - to 190 oF
PI - PTFE L shaped PTLI - to 190 oF
PII - All metal heaters over the side and thermowell. PII - to 180 oF (white # 3804)
PII-M 180 to 230 oF ( blue # 4047)
PII-H 230 to 300 oF (red # 2805)
PII - All metal L shaped heaters and flex riser. PLII - to 180 oF (white # 3804)
PLII-M 180 to 230 oF ( blue # 4047)
PLII-H 230 to 300 oF (red # 2805)
PII - Quartz heater PQII - to 180 oF (white # 3804)
PQII-M 180 to 230 oF ( blue # 4047)
PII - PTFE over the side PTII (to 190 oF)
PTIII (190 to 250 oF) - note (3) III
PII - PTFE L Shaped PTLII (to 190 oF)
PTLIII (190 to 250 oF) - note (3) III
PIII - PTFE with Flex Risers PIII  to 250 oF
All heaters will be supplied with the lowest temperature fuse unless specified otherwise.