ACI RTD Freezer Transmitter Series Sensor Instruction Manual

: June 9, 2024
: ACI

ACI RTD Freezer Transmitter Series Sensor

RTD Freezer Transmitter Series Sensor

Product Information

The ACI RTD Freezer Series sensors and transmitters are single point sensors that output 4-20 mA with an optional voltage signal output of 1-5VDC or 2-10VDC signal to BAS or controller. The temperature transmitters can be powered from either an unregulated or regulated 8.5 to 32 VDC power supply.

Mounting Instructions

Transmitter Enclosure Mounting

The transmitter must be mounted outside of the freezer/cooler. On Vertical units, mount on the top of the freezer. On Horizontal units, mount on the backside or side of the freezer. Attach the base directly to the wall by using double-sided tape.

Sensor Mounting

Bullet Probe sensors can be wrapped around a shelf. Alternatively, the sensor may be mounted on walls using a 1/4 mounting clip (ACI Item #108169). The sensor should be mounted in an area where air circulation is well-mixed and not blocked by obstructions. If a thermal buffer is required, use a glycol kit (ACI Item #130127). When using in tank or glycol application, ensure that the sensor’s end is kept above the liquid.

Wiring Instructions

All RTD’s are supplied with (2) or (3) flying lead wires. ACI’s transmitters are supplied with a 2 pole terminal block for RTD sensor connections. When wiring a 3 wire RTD, connect the (2) common wires (same color) together into the same terminal block.
Adding extra wire length between the sensor and transmitter board may affect accuracy.

Formula for Number of Transmitters

Several transmitters may be powered from the same supply. Each transmitter draws 25mA; refer to the following equation to obtain the number of permissible transmitters: [# Transmitters] = [Current] / (25 mA).

Product Usage Instructions

Mount the transmitter outside of the freezer/cooler using double-sided tape.
Wrap the Bullet Probe sensors around a shelf or mount them on walls using a 1/4 mounting clip.
Ensure that the sensor is mounted in an area where air circulation is well-mixed and not blocked by obstructions.
If a thermal buffer is required, use a glycol kit.
When using in tank or glycol application, ensure that the sensor’s end is kept above the liquid.
Wire the RTD sensor connections using the supplied 2 pole terminal block.
Refer to the formula to determine the number of permissible transmitters based on the current supply.

Phone: 1-888-967-5224
We b site: workaci.com

GENERAL INFORMATION

The ACI RTD Freezer Series sensors and transmitters are single point sensors that output 4-20 mA with an optional voltage signal output of 1-5VDC or 2-10VDC signal to BAS or controller. All ACI/TT and TTM temperature transmitters can be powered from either an unregulated or regulated 8.5 to 32 VDC power supply.

INSTRUCTIONS

ACI’s Freezer Series sensor includes a transmitter with enclosure and a 3/16” diameter stainless steel probe. The transmitter needs to be mounted in environments with ambient temperatures above -40 °C (-40 °F) – see SPECIFICATIONS (p. 4). The freezer probe’s operating temperature range is -200 °C (-328 °F) to 200 °C (392 °F).

ENCLOSURE MOUNTING

The transmitter must be mounted outside of the freezer/cooler. On Vertical units, mount on the top of the freezer see Figure 3 (p. 2). On Horizontal units, mount on the backside or side of the freezer. Attach the base directly to the wall by using double sided tape.

WIRE INSTALLATION

ACI recommends installing the wire through the door seal, probe access port, or cooler wall. On horizontal units, the preferred method is using the rear door seal as shown in Figure 4 (p. 2). On vertical units, remove the rear panel. There is typically a probe access hole. Probe and wires can be ran into that access hole. Alternatively, you can drill a hole just larger than the diameter of the wire (0.125” (3.175 mm)) through the wall. From inside the cooler/freezer, push the wire through the hole. Use mounting clips to secure the wire to the interior wall or shelving. Use silicone caulking to seal the hole around the wire.

SENSOR MOUNTING
Bullet Probe sensors can be wrapped around a shelf as shown in Figure 5.

FIGURE 1: FREEZER PROBE DIMENSIONS
FIGURE 2: ENCLOSURE DIMENSIONS
- GALVANIZED (-GD)
- NEMA 4X (-4X)
- BELL BOX (-BB)
  Alternative, the senor may be mounted on walls using a 1/4” mounting clip (ACI Item #108169). The sensor should be mounted in an area where air circulation is well-mixed and not blocked by obstructions. Slide the sensor probe through the mounting clip – see FIGURE 6. Drill a 1/4” screw through the socket and tighten to the wall. If a thermal buffer is required, use a glycol kit (ACI Item #130127). Drill pilot holes for the provided mounting screws. Use the mounting clip holes as a guide – see FIGURE 7. Drill the #10-16 x 1/2“ screws through the bracket holes and fasten it to the wall. Insert the bottle into the bracket, and make sure it is seated securely.
  Note: When using in tank or glycol application, the sensor cannot be fully submerged. The end of the probe must be kept above the liquid.
FIGURE 3: ENCLOSURE MOUNTING
FIGURE 4: WIRE ROUTING
FIGURE 5: SENSOR MOUNTING
FIGURE 6: SENSOR MOUNTING ON WALL
FIGURE 7: GLYCOL SENSOR w/ BRACKET

WIRING INSTRUCTIONS

PRECAUTIONS

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* Transmitter must be powered by 24 VDC only.
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- Remove power before wiring. NEVER connect or disconnect wiring with power applied.
- When removing the shield from the sensor end, make sure to properly trim the shield to prevent any chance of shorting.
- When using a shielded cable, ground the shield ONLY at the controller end. Grounding both ends can cause a ground loop.
If the 24 VDC power is shared with devices that have coils such as relays, solenoids, or other inductors, each coil must have an MOV, DC Transorb, Transient Voltage Suppressor (ACI Part: 142583), or diode placed across the coil or inductor. The cathode, or banded side of the DC Transorb or diode, connects to the positive side of the power supply. Without these snubbers, coils produce very large voltage spikes when de-energizing that can cause malfunction or destruction of electronic circuits.

Open the cover of the enclosure. ACI recommends 16 to 26 AWG twisted pair wires or shielded cable for all transmitters. Twisted pair may be used for 2-wire current output transmitters or 3-wire for voltage output. Refer to FIGURE 8 (right) for wiring diagrams. All wiring must comply with local and National Electric Codes. All ACI TT and TTM temperature transmitters can be powered from either an unregulated or regulated 8.5 to 32VDC power supply. The TT and TTM DO NOT support an AC input. All TT and TTM temperature transmitters are reverse polarity protected. After wiring, attach the cover to the enclosure.

Note: All RTD’s are supplied with (2) or (3) flying lead wires. ACI’s transmitters are supplied with a 2 pole terminal block for RTD sensor connections. When wiring a 3 wire RTD, connect the (2) common wires (same color) together into the same terminal block.

The minimum voltage at the transmitter power terminal is 8.5V after load resistor voltage drop.

249 Ω load resistor (1-5 VDC output) = 13.5 V min supply voltage
499 Ω load resistor (2-10 VDC output) = 18.5 V min supply voltage

Note: Adding extra wire length between the sensor and transmitter board may affect accuracy.

FORMULA FOR NUMBER OF TRANSMITTERS
Several transmitters may be powered from the same supply as shown in FIGURE 9 (p. 4). Each transmitter draws 25mA; refer to the following equation to obtain the number of permissible transmitters: [# Transmitters] = [Current] / (25 mA).

FIGURE 8: WIRING DIAGRAMS
STANDARD UNITS
- Current Output
  (4 to 20 mA)
- Voltage Output
  (1 to 5, 2 to 10VDC) POTTED UNITS
- Current Output
  (4 to 20 mA)
- Voltage Output
  (1 to 5, 2 to 10VDC)
FIGURE 9: MULTIPLE TRANSMITTER CONNECTIONS
- Connections
- AI1 = Controller Input #1
- AI2 = Controller Input #2
- AI3 = Controller Input #3

TROUBLESHOOTING

PROBLEM|
---|---
No Reading|

No power to board – check voltage at power terminal – should be between +8.5 and 32 VDC.

Reading too Low|

RTD wires shorted. Disconnect sensor wires from terminal block and check with ohmmeter. Reading should be close to either 100 or 1000 .
RTD Improper range of transmitter (too low). Check current or voltage (model dependent) – should be between 4-20 mA, 1-5 V, or 2-10 V.

Reading too High|

RTD opened. Disconnect sensor wires from terminal block and check with ohmmeter. Reading should be close to either 100 or 1000 .
Improper range of transmitter (too high). Check current or voltage (model dependent) – should be between 4-20 mA, 1-5 V, or 2-10 V.

Reading is Inaccurate|

Sensor check: Disconnect sensor wires from terminal block and check with ohmmeter. Compare the resistance reading to the Temperature vs Resistance curves located on ACI’s website.
Transmitter check: Make sure sensor wires are connected to terminal block. Determine that the proper output is being transmitted based on predetermined span:

Go to ACI Website, Span to Output Page: http://www.workaci.com/content/span-output
Enter the low end of the span
Enter the high end of the span
Click on the output of the transmitter. This will generate a span to output chart.
Measure output of transmitter.
Compare measured output to calculated output

RF Interference|

Input power must be clean. Use twisted wires or shielded cable. RF resistant power supply. Use a shielded cable to connect the sensor – connect the shield to ground. Encase the board in a RF shielded enclosure.

PRODUCT SPECIFICATIONS

SENSOR NON-SPECIFIC

Storage Temperature Range:| -40 to 80 °C (-40 to 176 °F)
Operating Humidity Range:| 10 to 95% RH, non-condensing
Lead Length | Cable Diameter:| 10’ (3.05 m) or 30’ (9.15 m) | 0.106” nominal (2.69 mm)
Lead Wire Insulation | Jacket Color:| FEP/FEP (Teflon) Jacketed Cable | White
Conductor Size | Conductor Material:| 24 AWG (0.51 mm) | Silver Plated Copper
Probe Material | Length | Diameter:| 316 Stainless Steel | 2” (50.8 mm) | 0.1875” (4.76 mm) nominal
Enclosure Specifications:| “-GD”: -40 to 100 °C (-40 to 212 °F); Galvanized Steel; NEMA 1 (IP10)
“-BB”: – 40 to 85 °C (-40 to 185 °F); Aluminum; NEMA 3R (IP 14)
”-4X”: -40 to 70 °C (-40 to 158 °F); Polystyrene Plastic, UL94-V2, IP66 (NEMA 4X)
TRANSMITTER
Transmitter Supply Voltage | Supply Current:| +8.5 to 32 VDC (Reverse Polarity Protected) | 25 mA minimum
250 !l Load (1-5VDC): +13.5 to 32 VDC | 500 !l Load (2-10VDC): +18.5 to 32 VDC
Output Signals:| Current: 4-20 mA (2-Wire Loop Powered) | Voltage: 1-5 VDC or 2-10 VDC (3-Wires)
Calibrated Transmitter Accuracy | Linearity:| T. Spans < 260 °C (500 °F): +/- 0.2% | T. Spans > 260 °C (500 °F ): +/- 0.5%
Transmitter Operating Temperature Range:| -40 to 85 °C (-40 to 185 °F)
Operating Humidity Range:| 0 to 90%, non-condensing
Calibrated Temperature Spans:| Min. T. Span: 28 °C (50 °F) | Max T. Span: 426 °C (800 °F )
Temp Drift| T. Span < 38 °C (100 °F): +/- 0.04% | T. Span > 38 °C (100 °F): +/- 0.02%
Warm Up Time | Drift| 10 Minutes | +/- 0.1%
Connections | Wire Size| Screw Terminal Blocks |16AWG(1.31mm2)to26AWG(0.129mm2)
Terminal Block Torque Rating| 0.5 Nm nominal
SENSOR
Sensor Type | Sensor Curve:| Platinum RTD | Linear, PTC (Positive Temperature Coefficient)
DIN Standard | Temp Coefficient| DIN EN 60751 (IEC 751) | 3850 ppm / °C
Response Time| 15 Seconds nominal
Sensor Output @ 0°C (32°F):| A/TT/TTM100-LTS Series: 100 | A/TT/TTM1K-LTS: 1 K
Sensor Tolerance Class | Accuracy:| +/- 0.12% Class B | Class B Tolerance Formula: +/- °C = (0.30 °C + (0.005 * |t|))
Sensor Operating Temperature Range:| -198 to 150ºC (-324 to 302ºF)

W.E.E.E. DIRECTIVE
At the end of their useful life the packaging and product should be disposed of via a suitable recycling center.
Do not dispose of with household waste. Do not burn.

WARRANTY

The ACI Freezer Temperature Series temperature sensors are covered by ACI’s Five (5) Year Limited Warranty, which is located in the front of ACI’S SENSORS & TRANSMITTERS CATALOG or can be found on ACI’s website: www.workaci.com.

Automation Components, Inc.
2305 Pleasant View Road
Middleton, WI 53562
Phone: 1-888-967-5224
Website: workaci.com