Schurter, Inc. •Phone 707-778-6311 • Fax 707- 778-6401 • E-mail info@schur ter inc.com • Website http://www.schurter inc.com 193
CIRCUIT BREAKERS FOR EQUIPMENT
1
TM12 Series
• Thermal magnetic release
• Positively trip-free
• Reset or manual
actuation
The TM12 circuit breaker for equipment (CBE) is a single pole, ther-
mal-magnetically operated device providing small size, low cost and
reliable trip-free operation on overloads and shor t circuits within the
maximum breaking capacity. It is intended primarily for the protection
of circuit control functions in sensitive instruments etc. It is not
generally suitable for line protection unless the prospective short cir-
cuit current is less than 200 A at 240 V a.c. (400 A at 28 V d.c.).
Threaded neck and flange mounting types are available each with
optional push on/push off mechanism, shunt terminal and auxiliar y
contact.There is also a choice of screw clamp terminals on cer tain
types.
The well proven mechanism is designed to open the contacts in the
event of over loads. A bimetal strip is heated by the overcurrent and
deflects, thereby releasing the latch mechanism. If the overcurrent is
sufficiently high, the magnetic release will operate and open the
circuit instantaneously.Two characteristics are available.The more
commonly used T characteristic has operating limits between 8-12
times the rated current.The optional F characteristic operates at a
lower current levels of 4-8 times the rated current.
In case of overloads, the contacts will open even if the reset button is
manually held in the closed position.This is known as a trip-free
feature.The contacts open and close with a snap action and the
tripped state is clearly shown by the increased projection of the reset
button. After the opening operation, the reset button has to be fully
depressed, then released, to effect a closing of the contact.
It is impossible to «tease» the contacts by gentle pressure on the
reset button.
Available options
• Fast and slow magnetic tripping characteristics
• Flange type
• Threaded neck type
• Type of actuation: reset or manual ON/OFF (push/push)
• Terminals: quick connect or screw clamp ter minals
• Independent auxiliary contact (change-over contact)
• Shunt terminal
• Setting indication on reset button indicates the position
of the contacts
Special features
• Competitive pricing
• Quick connect terminals
• Choice of mounting styles
• Positively trip-free
• Insensitive to shock or vibration
• UL, CSA, VDE and other approvals