Transmitter-SunShield

Supported Applications

The ACI Sun Shield is a weather-proof outdoor temperature transmitter assembly designed to protect a temperature sensor in outdoor environments where an overhang or shade is unavailable. It is built from nine molded white plastic plates that reduce solar thermal effects and increase airflow across the sensor, while also shielding it from rain and snow, so the transmitter reads true ambient air temperature rather than radiant sun load.

The assembly is supplied with a TT100 or TT1K Series 4-20 mA output temperature transmitter and reports to a building automation system (BAS) or controller. The housing is Polystyrene Plastic with a NEMA 4X (IP 66) rating, and the internal probe is 304 Stainless Steel, making the unit suited to rooftop and exposed outdoor air-temperature sensing.

Operating Conditions & Performance

The sensing element is a two-wire platinum RTD with a positive temperature coefficient (PTC) conforming to DIN EN 60751 (IEC 751). Sensor output at 32°F (0°C) is 100 Ohms nominal on the A/TT100 Series (Brown/Brown leads) or 1000 Ohms nominal on the A/TT1K Series (Black/Black leads), with a tolerance of +/- 0.06% Class A. Response time is 8 Seconds nominal at a 63% step change.

Transmitters are powered from a +8.5 to 32 VDC supply (reverse-polarity protected) drawing 25 mA minimum. Maximum load resistance tracks the supply: a 250 Ω load needs +13.5 to 32 VDC and a 500 Ω load needs +18.5 to 32 VDC. Output is 4-20 mA (2-Wire loop powered) current or 1-5 VDC or 2-10 VDC (3-Wires) voltage.

Calibrated accuracy is +/- 0.2% for temperature spans under 500°F (260°C) and +/- 0.5% for spans over 500°F (260°C); temperature drift is +/- 0.04%/°F for spans under 100°F (38°C) and +/- 0.02%/°F for spans over 100°F (38°C). The unit operates over -40 to 185°F (-40 to 85°C) and tolerates 0 to 90% RH non-condensing humidity. The internal probe is 0.25" (6.35mm) diameter with a 6.00" (152.4 mm) overall length, and the shield assembly measures 14.95" (379.7 mm) by 7.50" (190.50 mm), weighing 4.16 lbs (1.89 kg).

Configuration Options

The Sun Shield is offered with two transmitter elements. The A/TT100 build uses a 100 Ohms nominal platinum RTD, while the A/TT1K build uses a 1000 Ohms nominal element; both are calibrated to +/- 0.06% Class A and share the same shield hardware, output options and NEMA 4X (IP 66) housing.

Output type can be configured as a 4-20 mA (2-Wire loop powered) current signal or a 1-5 VDC or 2-10 VDC (3-Wires) voltage signal. Matched TTM transmitters may be ordered with NIST certification, with a default 3 Point NIST at 20%, 50% and 80% of span or an optional 5 Point NIST at 20%, 35%, 50%, 65% and 80% of span.

Key Product Differences

Part numbers follow the pattern A/<TEMPERATURE SENSOR>-O-SUN-<OUTPUT SIGNAL>-<CALIBRATED SPAN>, combining the sensor element, the O-SUN sunshield configuration and the output signal.

• Sensor element: TT100 (100 Ohms nominal) or TT1K (1000 Ohms nominal) platinum RTD.
• Configuration: the O-SUN outdoor sunshield assembly.
• Output signal: 4-20 mA (2-Wire loop powered) current or 1-5 VDC or 2-10 VDC (3-Wires) voltage.

The two catalog part numbers are A/TT100-O-SUN-4 and A/TT1K-O-SUN-4, distinguished only by the platinum RTD element they carry.