QAF63.2-J
8Pages

Catalog excerpts

Frost detectors QAF63.2-JQAF63.6-J for use on the air side • Active capillary tube sensor for acquiring the lowest temperature within a range of 0...15 °C • Operating voltage AC 24 V • Signal output DC 0...10 V

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Use On the air side of ventilation and air conditioning plants:  Typically: hot water air heating coils where there is a risk of freezing due to cold incoming outside air  Where fans are to be switched off, heating valves opened, air dampers closed or other actions need to be taken by the control system to prevent freeze-ups Functions Technical design With the help of a vapor-filled capillary tube and diaphragm, the QAF63.. acquires the lowest temperature which occurs along at least 250 mm length of capillary tubing. If the frost detector is correctly located at the air outlet of the air...

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Type summary Product number Accessories Included in the scope of delivery When ordering, please give product number, order number and description. The mounting accessories not included in the scope of delivery must be ordered as separate items. 1 x M16 cable gland for cable entry 2 x screw to DIN 7981-St 4.2 x 22 for direct mounting 1 x rubber grommet for capillary entries into air ducts Not included in the scope of delivery Product number Frost detectors

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Notes Engineering The frost detector operates on AC 24 V. The transformer used must be suitable for safety extra low voltage (SELV), 100% duty, and must have separate windings. Fuses, switches, wiring and earthing must be in compliance with local safety regulations. The permissible cable lengths must be observed. If the capillary tube is mechanically damaged or if there is a leak in the diaphragm system, the frost detector signals a temperature of 0 °C. That is the case also if there is a power failure or if one of the major electronic components fails. Mounting Mounting location On the hot...

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Technical data Power supply Operating voltage Frequency_ Power consumption At ambient temperatures >10 °C (with no heating)_ External supply line protection Circuit breaker max. 10 A Characteristic B, C, D according to EN 60898 or Power source with current limitation of max. 10 A Line lengths for measure signal terminals B -Functional data Perm. cable length Copper cable 1.5 mm_300 m_ Time constant: In still air Approx. 90 s _In moving air_<40 s_ Output signal, linear (terminal B) DC 0...11.5 V = 0...15 °C Degree of protection Electrical connections Environmental conditions Capillary tube...

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▼ ▲ G System voltage (SELV) AC 24 V M System neutral, measuring neutral B Signal output DC 0...11.5 V ^ 0...15 °C Note: If terminal "B" of the QAF... is connected to a controller, signal >10 V might drop out (e.g. 11 V) which, with certain types of controllers, can lead to a fault status message. Remedy: Fit a Zener diode to terminal "B" of the QAF.. or to the controller’s input to ensure that the DC 0.10 V signal will not exceed 10 V. Frost detectors

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Frost detectors

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Published by: Siemens Switzerland Ltd. Smart Infrastructure Global Headquarters Theilerstrasse 1a CH-6300 Zug Switzerland Tel. +41 58-724 24 24 © Siemens Switzerland Ltd 2014 www.siemens.com/buildingtechnologies Delivery and technical specifications subject to change Frost detectors

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