Data Sheet for Product

ManualsBrandsSiemens ManualsThermostats (temperature controller with sensor)Frost detectors QAF64..-J

A6V10432022_en--_e

2021-04-20

Smart Infrastructure

Frost detector

QAF64.2-

QAF64.6-J

for use on the air side

 With active capillary tube sensing element for acquiring the lowest

temperature within a range of 0…15 °C

 With startup function

 Operating voltage AC 24 V

 Signal voltage DC 0...10 V

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 and air dampers

closed to prevent freeze-ups

 Where risk of frost shall be signaled

Summary of content (10 pages)

PAGE 1
Frost detector QAF64.2-J QAF64.6-J for use on the air side  With active capillary tube sensing element for acquiring the lowest temperature within a range of 0…15 °C  With startup function  Operating voltage AC 24 V  Signal voltage DC 0...
PAGE 2
Functions Technical design With the help of a vapor-filled capillary tube and diaphragm, the QAF64… acquires the lowest temperature which occurs along at least 250 mm length of capillary tubing. When correctly located at the air outlet of the air heating coil, the frost detector acquires the lowest air temperature even in the case of temperature stratification. The vapor pressure in the capillary tube produces a certain travel of the diaphragm.
PAGE 3
Operating modes Three operating modes can be selected: Automatic operation "Auto" If, after shutdown due to frost, the capillary tube temperature rises (>2 K), the output relay will automatically return to its normal position. Manual operation "Manu" If, after shutdown due to frost, the capillary tube temperature rises (>2 K), the output relay will return to its normal position only if either the inbuilt reset button is pressed or the power supply is cut off (e.g. via an external reset button).
PAGE 4
Type summary Product number QAF64.2-J QAF64.6-J Ordering Stock number S55700-P155 S55700-P156 Description Frost detector with 2-m capillary Frost detector with 6-m capillary When ordering, please give product number, stock number and description. The mounting accessories not included in the scope of delivery must be ordered as separate items. Accessories Included in the scope of delivery Not included in the scope of delivery 1x 2x 1x M16 cable gland for cable entry screw to DIN 7981-St 4.
PAGE 5
Mounting Mounting location Mounting of housing On the hot side of the air heating coil. Direct mounting Fit the housing (by using the 2 fixing holes) to the wall of the air heating coil. Introduce the capillary tube in the air duct and protect it by using the rubber grommet supplied with the unit (refer to "Accessories"). When fitting the frost detector inside the air duct: secure the housing to the inner wall of the air heating coil and lead the capillary tube through one of the lateral grooves.
PAGE 6
Technical data Power supply Analog input Analog outputs Relay output (terminals Q11, -12 , -14) Functional data Degree of protection Electrical connections Environmental conditions AC 24 V 20% (SELV) 50/60 Hz Max. 6.6 VA Circuit breaker max. 13 A Characteristic B, C, D according to EN 60898 or Power source with current limitation of max. 13 A Valve control (terminal Y) DC 0...10 V Current Max. 0.1 mA 2 Perm. cable length with 1.5 mm 300 m Sensing element temperature (terminal B) DC 0...11.5 V ≙ 0...
PAGE 7
Materials and colors Directives and standards Weight Base PA (RAL 7001, silver-grey) Cover Cap Capillary tube Packaging PC (transparent) ABS, (RAL 7035, light-grey) Copper Corrugated cardboard Product standard Environmental compatibility EN 60730-1 The product environmental declaration 8000079858 *) contains data on environmentally compatible product design and assessments (RoHS compliance, materials composition, packaging, environmental benefit, disposal). 8000036003*) Approx. 0.34 kg Approx. 0.
PAGE 8
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.
PAGE 9
Connection diagram F1 Frost detector QAF64... N1 Controller delivering a DC 0...10 V control signal H1 E.g. external frost alarm device K1 E.g. fan contactor P1 E.g.
PAGE 10
Dimensions (Dimensions in mm) Published by: Siemens Switzerland Ltd. Building Technologies Division International Headquarters Theilerstrasse 1a CH-6300 Zug Switzerland Tel. +41 58-724 24 24 www.siemens.