FC21-22

Supported Applications

The Omega FC-21 and FC-22 multifunction flow computers are designed for a variety of flowmeter applications. The FC-21 model is specified for liquid batching, volumetric batching, and corrected-volume applications. The FC-22 model extends this capability to include gas, steam, and heat applications in addition to liquids.

Both models support multiple measurement types including volume flow, corrected-volume flow, mass flow, temperature, pressure, density, and heat flow. They are programmable from the front panel to store multiple flow equations suitable for these processes.

Operating Conditions & Performance

The series operates within an ambient temperature range of 0 to 50°C (32 to 122°F). Storage temperatures are rated from -40 to 85°C (-40 to 185°F), with a maximum relative humidity rating of 0 to 95%, non-condensing.

Input measurement ranges support various signal types:

• Voltage: 0 to 10 Vdc, 0 to 5 Vdc, and 1 to 5 Vdc (FC-21 only)
• Current: 4 to 20 mA and 0 to 20 mA
• Pulse Inputs: Low-Level Pulse at 10 mV or 100 mV; High-Level Pulse with low = 0 to 1 Vdc and high = 3 to 30 Vdc
• Frequency: Up to 20 kHz maximum count speed

The FC-21 features a programmable excitation voltage of 5, 12, or 24 Vdc @ 100 mA. The FC-22 provides a fixed excitation at 24 Vdc.

Physical Dimensions and Enclosure

The standard panel mount dimensions are 144 mm (5.7 in) width by 87 mm (3.4 in) height, with a depth of 156 mm (6.2 in). The required panel cutout is 138 mm (5.4 in) wide by 68 mm (2.7 in) high.

Enclosure options include the standard DIN enclosure and an optional NEMA 4 (IP65) wall mount configuration. An explosion-proof box option is also available for specific hazardous environments, though this housing restricts front panel button access.

Outputs and Communications

The series provides isolated analog outputs configurable as volume flow, corrected volume flow, mass flow, heat flow, temperature, pressure, or density. Output signal types include 4 to 20 mA, 0 to 20 mA, 0 to 10 Vdc, 0 to 5 Vdc, and 1 to 5 Vdc (FC-21 only). The FC-22 also supports an open collector output at 24 Vdc.

Standard communication includes an RS-232 serial port for data logging, transaction printing, or remote meter reading. An optional RS-485 serial interface is available via the -RS485 suffix option.

Configuration Options

The FC-21 and FC-22 series offer extensive configuration options to meet specific installation requirements:

• Display Types: Standard LCD or optional VFD (Vacuum Fluorescent Display) for enhanced visibility.
• Housing Configurations: DIN panel mount, NEMA 4 (IP65) wall mount, and explosion-proof box enclosures.
• Power Supplies: FC-21 supports standard 110 or 220 Vac with optional 12 Vdc or 24 Vdc. FC-22 features a wide-range AC input of 85 to 275 Vac, 50/60 Hz as standard, with an optional 24 Vdc supply.
• Advanced Options: Data logging (64k battery-backed RAM), peak demand calculation, natural gas compensation (NX-19 option for compressibility effects), stacked differential pressure transmitter support, and language translation options.

Key Product Differences

The primary distinction between the two models lies in their application scope. The FC-21 is designated specifically for liquid applications including batching and corrected-volume calculations. The FC-22 encompasses all capabilities of the FC-21 while adding support for gas, steam, and heat flow equations.

Model suffixes denote specific configurations:

• -V: Indicates a VFD display (e.g., FC-21-V).
• -NEMA: Denotes the NEMA 4 (IP65) wall mount enclosure.
• -EXP: Specifies factory mounting inside an explosion-proof box with no button access.
• -RS485: Adds RS-485 serial communication capability.

Power options are indicated by suffixes such as -12VDC, -24VDC, and -220VAC. The FC-22 standard power supply covers 85 to 275 Vac, whereas the FC-21 requires specific voltage selection (110 or 220 Vac) unless configured with DC options.