Current-Relay Type STW12V

The basic function of the device is to detect whether a current is flowing in the supply line of one of several woodworking machines. If a current flow is detected, the device switches on a suction system. When the last machine is switched off, the device stops the extraction system after a delay.

Current relays in OR evaluation with 12 inputs, designed e.g. for controlling of suction plants in the timber and plastics processing industry.

Recording of current is made with current transformers type STWA 1, current-sensors S 1 (DC also) or potential-free contacts. When there is an AC-current higher than the set response value (setting range 0.5 - 5A) through at least one of the connected transformers , the integrated relay (1 NO) picks up. If all monitored circuits are switched off or the current falls below the set response value by approx. 0.3 A, the output relay releases after the set time delay (1 - 60). 

Due to the adjustable response value, the user can permit lower currents without releasing switchings. Thus, for example, a machine can be switched on in order to adjust its electronic settings (low current via transformers). The STW will only switch on when the main motor has been put into operation (high current). Due to the adjustable switch off delay an easy adjustment of the follow-on is possible.

• Current monitoring of up to 12 currents
• Inputs for current transformers STWA 1, current-sensors S1 or potential-free contacts
• Adjustable switching point 0.5 - 5 A
• Adjustable switch off delay (1 - 60 s)
• Plug-in terminals
• Universal supply-voltage AC/DC 24-240 V
• Housing for mounting in switchgear cabinets or fuseboxes, 70 mm wide, mounting height 55 mm

Application

ZIEHL current monitors in OR-circuits can be used particularly where dust, fumes and gases are generated by various electrical devices, and where these must be extracted by a central suction system. Due to the integrated delaytime the follow-on of the suction is controlled.