Transcript
OUTDOOR ASPIRATED HUMIDITY/ TEMPERATURE SENSOR HOUSING MODEL A21
TM
SOLUTIONS
DESCRIPTION Model A21 Outdoor Aspirated Humidity/ Temperature Housing provides powered aspiration for outdoor monitoring of humidity and temperature. The NEMA 3R enclosure is painted white to reduce the effect of radiation, and the enclosure has a lockable latch for security. OPERATION The fan pulls air in from the lower vent intake and exhausts the air out the upper opposing vent of the enclosure. The 24 VDC power is supplied for both the fan and transmitters. The transmitter power is internally filtered from any fan motor noise that might affect the transmitter signal.
SPECIFICATIONS Supply voltage
24 VDC @ 110 mA (add power requirements for the humidity/temperature transmitters) 47Ω added to the 4-20 mA transmitter 6 lb (2.72 kg) Washable pocket foam filter
Impedance Weight Air filter
Temp range
Enclosure Hinge
-40° to 120°F (-40° to 49°C) (see “Related Products” section for added temperature requirements) NEMA 3R with white enamel paint and latch for padlock Piano-type, left-hand side
DIMENSIONS
Air Exhaust 9.0 (22.86)
Left Side
Front View 3.0 (7.62)
0.5 (1.27)
5.0 (12.7)
1.0 (2.54)
1.75 (4.44) Terminal Strip (projected forward 3.5 (8.89) for easy wiring) 5.25 (13.34)
10.0 (25.40)
Air Intake
0.5 (1.27)
4.7 (12.06)
Fan
0.20 (0.50)
in (cm)
A B CD E F
3.65 (9.27)
1.0 (2.54)
6.5 (16.51)
Lower Back Plate* 4.25"W x 4.25"H x 3"D
Right Side
0.5 (1.27) 7.0 (17.78) 6.32 (16.05)
0.25 (0.64) 0.5" and 0.75" knockouts on centerline and height shown
Bottom View
0.37 (0.95) Conduit Entry 1/2" & 3/4" Knockouts *Estimated usable dimensions
1.64 (4.15)
3.0 (7.62)
Mounting
KELE • www.kele.com • FAX 901-372-2531
Interior
USA 901-937-4900 • International 901-382-6084 May 2003
WIRING Connect the 24 VDC power to the terminals C(–) & D(+) as shown. Connect transmitter power from B(+) & E(return). Connect the monitoring controller to the C(–) & E(sig.+) terminals. Solidly ground the metal enclosure to provide a safe path for lightning surges. CAUTION: The monitoring controller ground (–) should be wired directly from the A21 terminal C(–), not from the ground (–) of the power supply. Even though these two points are electrically the same, a ground loop can occur because of the higher current draw of the fan motor. This current could produce a large enough voltage drop to affect the transmitter readings.
Dry bulb temperature
A21
To Controller * Input 24VDC Power Supply
A
D
B C
+
E
F
– +
Not used
Do not use or terminate
A21 D 4 VDC
M
– 4-20 mA to + controller input
Transmitter
47 Ω
E
B 470 μF
Motor
Controller Input
A
+
–
Transmitter
C
Heavy lines represent field terminations.
* Temperature sensors are directly wired to the controller. They do not wire to the terminal strip.
MOUNTING & INSTALLATION Location: Install the Model A21 enclosure where the ambient temperature is within the specified operating environment of the enclosure and installed transmitters. Select a location shielded from the sun so that the humidity and temperature readings are not affected by the additional building heat radiation. Poor locations include above sunexposed walls, windows, doors, and exhaust vents or under eaves, which can capture or expel tempered air. Mounting: Mount vertically using the four holes on the top and bottom flanges. The conduit entry is on the bottom with either 1/2" or 3/4" conduit knockouts. Conduit entry from the side or top is ill-advised due to potential water penetration.
CAUTION: Remove the knockout on the bottom of the enclosure very carefully. Transmitters that are mounted above the knockouts may be damaged.
CHECK-OUT Apply power to the Model A21 after all the installation and wiring is complete. The fan should run immediately, and all transmitters should start to operate. There are no adjustments or calibrations required for the Model A21 components. Follow the manufacturers recommendations for the transmitter checkout. ORDERING INFORMATION MODEL A21
HW10K HW20K CT-829-A-MH ST-R◊R ST-R81 ST-R91S ST-R78 T102-O-F T102-O-I PN46 A21-FAN 4TK248 KELE • www.kele.com • FAX 901-372-2531
DESCRIPTION Aspirated Sensor Housing RELATED PRODUCTS 3% Wall mount humidity sensor 2% Wall mount humidity sensor 2% Wall mount humidity sensor PreCon thermistor 100Ω Platinum 385 1000Ω Platinum 375 2000Ω Balco, 4.96Ω/°F Solid-state temperature sensor Solid-state temperature sensor Mounting clip for temperature sensor Replacement fan assembly Snap track for the HW10K, HW20K USA 901-937-4900 • International 901-382-6084
