CZ1 - Thermal-Protectors without insulation cap

Product catalog summary

Specifications:
Diameter: 9.4 mm
Height: 5.0 mm
Length of insulation cap: 19.0 mm

Application:
The SZ1 thermal protector is designed for overheating protection in electrical equipment, particularly transformers, as per EN 60 742. It is sensitive to both temperature and current, making it suitable for scenarios with rapid temperature increases due to overloads or short circuits.

Design:
The SZ1 is based on Thermik's series 01 mechanism, featuring a series resistor RS for defined current sensitivity. It includes an insulation cap.

Operation:
Upon reaching the rated switching temperature, the bimetallic disc snaps open the contact. It resets automatically after cooling.

Series Resistor RS:
The RS must be tailored to each application, with a recommended heating performance of 5 W to 10 W for optimal response time under short circuit conditions. Experimental testing is advised to determine the best fit.

Features:

Quick response due to metal housing and small mass
Defined response time of less than 20 seconds
Long-term performance with fine-silver contacts
Instantaneous switching with consistent contact pressure
Short contact bounce time of less than 1 ms
High temperature resistance

Technical Data:

Contact type: Normally closed (NC)
Nominal switching temperature: 70°C to 160°C in 5 K steps
Standard tolerance: ±5 K
Resetting temperature: >35°C
Rated voltage: 250 V AC
Rated current: 2.0 A (cos φ = 1.0); 1.6 A (cos φ = 0.6)
Max switching current: 4.0 A at 250V~
Contact resistance: <50 mΩ
Vibration proof: 100 m/s² at 10-60 Hz
Dielectric strength: 2 kVr.m.s.
Standard connection leads: Multi-strand wire, 0.25 mm², 100 mm length, white, insulation class H
Approvals: VDE, CB Scheme

Short Circuit Currents and Series Resistor Values:
A table provides short circuit current ranges and corresponding RS values in ohms, with other nominal resistance values available upon request.

Ordering Information:
Example format: SZ1 - 125 . 05 . 0100 / 0100 . 1,1

Note:
Specifications may vary for special designs, and technical specifications are subject to change without notice.

Catalog excerpts

CZ1 - Thermal-Protectors without insulation cap-1

The current sensitive thermal protector type SZ1 with normally closed contacts is utilised for overheating protection of all electric equipment or devices, especially to safeguard transformers according to EN 60 742. The type SZ1 is sensitive for temperature as well as for currents. Therefore it is recommended in all cases of a dramatic rise of temperature, due to an overload current, e.g. in case of short circuit. > The thermal protector SZ1 is based on the well proven mechanism of Thermiks product series 01. A defined current-sensitivity is reached by an integrated series resistor > S . Version: SZ1 with insulation cap > Diameter d 9.4 mm Height h 5.0 mm Length of insulation cap l 19.0 mm dimensions (average) If, in the case of overheating or increase in current, the rated switching temperature of the bimetallic disc is reached, this suddenly snaps over and opens the contact. Automatic resetting after a significant temperature drop. TP of Type SZ1 R > S U > L The series resistor R > S has to be adapted to each application. To protect an electrical apparatus, the response time should be less than 20 seconds in case of a short circuit. In order to guarantee this ideal response time, a heating performance of R > S between 5 W and maximal 10 W is recommended. The table on the next side will help to find an optimal resistor R > S . Due to different possibilities of adapting the protector to the electrical device, experimental tests with different protectors are recommended. > Quick response sensitivity: featured by the metal housing and small protector mass Defined response time: < 20 s , due to series resistor R > S Excellent long term performance : due to fine-silver contacts. Reproducible switching temperature values due to tempered, electrically and mechanically unstressed bimetallic disc Instantaneous switching: with constant contact pressure over the whole temperaturerange Very short bounce times: < 1 ms Temperature resistance: by use of high temperature resistant materials and components > Thermik GerҤtebau GmbH ? P.O. Box 101980 ? D-75119 Pforzheim ? Germany ? Phone: +49 (72 31) 60 04 -0 ? Fax: +49 (72 31) 60 04 -100 size="-2">

Open the catalog to page 1

All Thermik catalogs and technical brochures

Archived catalogs

Standard Products
4 Pages