Product Overview

YGM Motor Protectors PTC (Positive Temperature Coefficient) Thermistors are designed for rapid response thermal protection of electrical machines. These compact PTC thermistors are easily assembled into windings and feature flexible connecting leads. They offer a non-linear resistance/temperature response, rapidly increasing to a very high value at a specified temperature, effectively acting as a thermal switch. Available with or without an insulated sleeve, they are ideal for monitoring the windings of electric motors and for use in simple fail-safe circuitry. When the nominal response temperature is exceeded, the PTC sensor's extremely high ohmic value can trigger a shutdown via a relay or amplifier, mimicking a circuit break or thermistor failure.

Product Attributes

• Brand: YGM
• Type: PTC (Positive Temperature Coefficient) Thermistors
• Features: Rapid response protection, Compact size, Silvered copper leads, Available with or without insulated sleeve, Flexible connecting leads
• Conductors: Silvered copper wire with Teflon insulation (PTFE)
• Conductor cross-section: 0.25 mm (for single, double, and triple PTCs)
• Insulation stripping: Approx. 10 mm
• Origin: Canada (Implied by contact information)

Technical Specifications

* One PTC might reach NAT + 15 C, while the second or even both of the others could still remain at room temperature.

PTC's are classified according to their nominal response temperature NAT but all have similar resistance characteristics to simplify the choice of switching device. The relationship of resistance to temperature of all these PTCs is as follows: The greatest resistance change occurs between 5 C either side of NAT, being at least 15%/K.

PTC thermistors exhibit very high sensitivity over a narrow temperature band. For temperature measurement in this range, NTC thermistors are easier to measure and more accurate.

PTC thermistors are especially suited as temperature sensors for monitoring the windings of electric machines, and also for use in simple fail-safe circuitry.

PTCs are also available in many special housings (can be manufactured to customers specifications).

Random testing is carried out according to DGQ P90/P10 (DIN 40080). AQL values can be fixed by arrangement.

Installation tips for PTC temperature sensors in electrical windings:

• The thermistors can only be inserted in the windings before impregnation.
• It is advisable to embed one in each phase, if possible in the centre of the coil generating most heat, and generally on the outflow side of any air movement.
• Air inflow onto the temperature sensor will interfere with heat transfer.
• If using varnish/lacquer which is not chemically neutral, suitability tests must be undertaken by the customer.
• WARNING! It is very important that the sensor must be installed parallel with the copper of the winding, so that the teflon leads can assume the form of the rest of the winding and thereby retain the high-voltage resistance rating.