Mercoid Series SBLTX Submersible Level Transducer

Product Overview

The Mercoid Series SBLTX Submersible Level Transducer is engineered for reliable, long-term service in demanding environments. It features a piezoresistive sensing element housed in a robust 316 SS body with a protective bullet nose design. The transducer is supplied with a 270-pound tensile strength, shielded, vented cable. The integrated ventilation tube in the cable automatically compensates for changes in atmospheric pressure above the liquid surface.

Specifications

Service

Compatible liquids.

Wetted Materials

• Body: 316 SS, 316L SS
• Bullet nose: PVC
• Cable: Polyether polyurethane or ETFE
• Seals: Fluoroelastomer

Performance

• Accuracy: ±0.25% of Full Scale (FS)
• Temperature Limit: ETFE cable: -4 to 176°F (-20 to 80°C); Polyurethane cable: -4 to 149°F (-20 to 65°C)
• Compensated Temperature Range: -4 to 176°F (-20 to 80°C)
• Thermal Effect: Less than ±0.02% FS/°F
• Pressure Limit: 2X FS
• Response Time: 50 ms
• Max. Loop Resistance: 900 Ω

Electrical

• Power Requirement: 10-28 VDC
• Output Signal: 4-20 mA DC, 2-wire

Physical

• Electrical Connections: Wire pigtail
• Mounting Orientation: Suspended in tank below the measured level
• Weight: 2.2 lb (1.0 kg)

Compliance

• CE, UKCA. Refer to Intrinsic Safety Approval Classification for details.

Intrinsic Safety Approval Classification

The SBLTX is UL listed for use in Hazardous (Classified) Locations, employing Intrinsic Safety ("ia") protection. It has been investigated by UL under UL Standard 913 8th Edition and CAN/CSA C22.2 No. 60079-0:15 and CAN/CSA C22.2 No. 60079-11:14.

Hazardous (Classified) Location Intrinsically Safe For:

• Class I Div. 1 Groups A,B,C,D
• Class II Div. 1 Groups E,F,G
• Class III Div. 1
• Class I Zone 0 AEx ia IIC T4 Ga
• Zone 20 AEx ia IIIC T135°C Da
• Ex ia IIC T4 Ga
• Ex ia IIIC T135°C Da

Temperature Ratings:

• ETFE Cable: Ta = -20°C to 80°C
• Polyurethane Cable: Ta = -20°C to 65°C

Control Drawing References:

Install in accordance with Control Drawing 001833-43. See Control Drawing 001833-43 for Entity Parameters.

ATEX Approval:

EU Type Certificate NO. DEMKO 18 ATEX 2080. ATEX STANDARDS: EN 60079-0, EN 60079-11. ATEX CLASSIFICATION: CE2813 II 1 G Ex ia IIC T4 Ga (-20°C ≤ Tamb ≤ 80°C (ETFE Cable)) / (-20°C ≤ Tamb ≤ 65°C (Polyurethane Cable)); CE2813 II 1 D Ex ia IIIC T135°C Da (-20°C ≤ Tamb ≤ 80°C (ETFE Cable)) / (-20°C ≤ Tamb ≤ 65°C (Polyurethane Cable)).

IECEx Approval:

IECEx Certificate of Conformity: IECEx UL 18.0086. IECEx STANDARDS: IEC 60079-0, IEC 60079-11. IECEx CLASSIFICATION: Ex ia IIC T4 Ga (-20°C ≤ Tamb ≤ 80°C (ETFE Cable)) / (-20°C ≤ Tamb ≤ 65°C (Polyurethane Cable)); Ex ia IIIC T135°C Da (-20°C ≤ Tamb ≤ 80°C (ETFE Cable)) / (-20°C ≤ Tamb ≤ 65°C (Polyurethane Cable)).

UKCA Ex Approval:

UKCA Ex: CERTIFICATE UL21UKEX2364. UKCA Ex STANDARDS: EN 60079-0, EN 60079-11. UKCA Ex CLASSIFICATION: II 1 G Ex ia IIC T4 Ga (-20°C ≤ Tamb ≤80°C. Install in accordance with Control drawing 001833-46. See Control Drawing 001833-46 for Entity Parameters.

Safety Warning

⚠️ Use with approved safety barriers using entity evaluation.

Installation Instructions

CAUTION

Do not exceed specified supply voltage ratings. Permanent damage not covered by warranty will result. This device is not designed for 120 or 240 VAC operation. Use only on 10-28 VDC.

1. Location

Select a location where the ambient temperature of the transducer will be between -4 and 176°F (-20 to 80°C) for ETFE cable or -4 and 149°F (-20 to 65°C) for polyurethane cable. The distance from the receiver is limited only by the total loop resistance.

2. Position

The transducer is not position sensitive. However, all standard models are originally calibrated with the unit in a position with the pressure connection downward. For best accuracy, it is recommended that units be installed in the position calibrated at the factory, though they can be used at other angles.

3. Mounting

The transducer can be mounted using several methods: suspended from the electrical cable, placed resting on the bottom of the tank (horizontal or vertical orientation), or attached to a pipe or hang wire using the 1/2" NPT male connection on the top of the housing.

4. Electrical Connections

Wire Length Considerations

The maximum length of wire connecting the transducer and receiver depends on wire size and receiver resistance. Wiring should contribute no more than 10% of the receiver resistance to the total loop resistance. For very long runs (over 1000 feet), select receivers with higher resistance to minimize wire size and cost. For wiring under 100 feet, wire as small as 22 AWG can be used.

Wiring Requirements

An external power supply delivering 10-28 VDC with a minimum current capability of 40 mA DC per transducer is required to power the control loop. The maximum receiver load resistance (RL) for the DC power supply voltage is calculated using the formula: RL Max = (Vps - 10 V) / 20 mA DC.

Shielded Cable

Shielded cable is recommended for control loop wiring.

Wiring Diagram (Figure A)

Diagram Description: This diagram illustrates the basic wiring for a 4-20 mA 2-wire loop. A PRESSURE TRANSDUCER (with RED wire for positive [+] and BLACK wire for negative [-]) is connected in series with a RECEIVER and a 10-28 VDC POWER SUPPLY. The loop carries a 4-20 mA signal.

Terminal Connections (Figure B)

Diagram Description: This diagram indicates the polarity for the transducer's electrical connections. The BLACK wire is negative [-] and the RED wire is positive [+].

Maintenance

After final installation of the pressure transducer and its companion receiver, no routine maintenance is required. A periodic check of system calibration is suggested.

The Series SBLTX transducer is not field repairable. If repair is needed, it should be returned to the manufacturer. Field repair attempts may void the warranty. When returning the unit, include a brief description of the problem and any relevant application notes. Contact customer service to receive a return goods authorization (RGA) number before shipping.

Intrinsic Safety Control Drawing

This section details the intrinsic safety parameters and installation requirements for the SBLTX transducer in hazardous locations.

Notes:

• Selected associated apparatus must be third-party listed as providing intrinsically safe circuits and must not exceed the entity parameters listed in the drawing.
• Associated apparatus output current must be limited by a resistor to ensure the output voltage-current plot is a straight line between open-circuit voltage and short-circuit current.
• Capacitance and inductance of field wiring must be calculated, including system calculations. Total capacitance is the sum of factory cable capacitance (CSBLTX CABLE) and end-user cable capacitance (CCABLE). Total inductance is the sum of factory cable inductance (LSBLTX CABLE) and end-user cable inductance (LCABLE).
• Specific capacitance and inductance values for Polyurethane cable are 96 pF/ft (315pF/m) and 346 nH/ft (1.135µH/m), respectively. For ETFE cable, values are 162 pF/ft (532 pF/m) and 340 nH/ft (1.116µH/m). If unknown, use 60 pF/ft (200pF/m) and 0.2 µH/ft (1.0 µH/m). The SBLTX cable length must be multiplied by these parameters based on the device's cable type.
• Transducers must be installed according to the manufacturer's control drawing and relevant electrical codes (e.g., NEC Article 504 in the US, CSA C22.1 in Canada).
• Associated apparatus manufacturer's installation instructions must be followed.
• The cable used has a vent tube; therefore, the cable attached to the SBLTX must be terminated in the hazardous area.
• No revisions to this drawing are permitted without prior approval by UL/DEMKO.
• Transducer must be installed in accordance with IEC/EN 60079-14 or local installation codes.

Transducer Entity Parameters (Hazardous Area):

• Ui (Max. Input Voltage): 28 VDC
• Ii (Max. Input Current): 93 mA
• Ci (Max. Internal Capacitance): 0.037µF + (CSBLTX CABLE)
• Li (Max. Internal Inductance): 15.92µH + (LSBLTX CABLE)
• Pmax(Pi) (Max. Power): 651 mW
• Gas Groups: IIC, IIIC

Associated Apparatus Entity Parameters (Non-Hazardous Area):

• Voc (Vo) (Max. Output Voltage): ≤ 28V
• Isc (lo) (Max. Output Current): ≤ 93mA
• Po (Po) (Max. Output Power): ≤ 0.651W
• Ca (Co) (Min. External Capacitance): ≥ 0.037µF + (CSBLTX CABLE) + (CCABLE)
• La (Lo) (Min. External Inductance): ≥ 15.92µH + (LSBLTX CABLE) + (LCABLE)

Control Drawing Diagram Description

Diagram Description: This diagram illustrates the intrinsic safety circuit for the SBLTX transducer. It depicts the connection between a TRANSDUCER located in a HAZARDOUS AREA and ASSOCIATED APPARATUS in a NON-HAZARDOUS AREA. The system uses a 4 to 20mA SIGNAL transmitted via RED and BLACK wires. The diagram specifies entity parameters for both the transducer (Ui, Ii, Ci, Li, Pmax for gas groups IIC and IIIC) and the associated apparatus (Voc, Isc, Po, Ca, La). It includes notes on calculating total system capacitance and inductance by adding factory cable values to end-user cable values, the presence of a vent tube requiring termination in the hazardous area, and the need for proper grounding. Optional shield connections are also shown.