DS3820TIMC GE | Speedtronic Temperature Card | OEM Surplus

Description

Product Introduction

The GE DS3820TIMC is a universal temperature input module for the Speedtronic Mark V turbine control system, providing eight isolated channels that support thermocouples, RTDs, and 4-20 mA temperature transmitters in a single board. This module mounts directly into the Mark V rack and interfaces with the backplane, converting temperature sensor signals into accurate digital readings for the CPU.

The “TIMC” designation indicates “Temperature, Input, Multi-Configurable” — the defining feature being the ability to configure each channel independently for thermocouple (J, K, or T), RTD (Pt100 or Ni120), or 4-20 mA transmitter input. This universal capability eliminates the need to stock separate TC, RTD, and analog input modules, significantly simplifying spare parts inventory and providing maximum flexibility for mixed-sensor applications. The board is particularly valuable in turbine retrofits where existing sensors include a mix of thermocouples, RTDs, and smart transmitters.

Key Technical Specifications

Key Selling Points & Differentiators

• Three sensor types in one board. Supports thermocouples, RTDs, and 4-20 mA temperature transmitters—eliminating the need for separate TC, RTD, and analog input modules.
• Configurable per channel. Each of the 8 channels can be independently configured for any supported sensor type through the Mark V software—no hardware jumpers required.
• Internal 4-20 mA loop power. No external power supply needed for loop-powered transmitters—the TIMC provides 24V loop power internally.
• Automatic RTD lead compensation. For 3-wire and 4-wire RTD configurations, lead resistance is automatically compensated.
• Integrated cold junction compensation. For thermocouple mode, no external reference junctions required.
• Open sensor detection for all modes. Continuous monitoring for broken wires, open circuits, or transmitter faults, with diagnostic reporting to the CPU and a yellow LED indicator.
• 48-hour burn-in with accuracy verification for all three modes. Every unit is tested with precision millivolt sources (TC mode), precision decade boxes (RTD mode), and precision current sources (4-20 mA mode). Accuracy verified across the full operating range in all three modes.
• 18-month warranty covering accuracy and channel integrity for all sensor types. If any channel fails to maintain accuracy in any mode, we replace the board.

Frequently Asked Questions (FAQ)

Q: What is the difference between the T1MC and the TIMC?

A: Two key differences: (1) the TIMC adds 4-20 mA temperature transmitter support in addition to thermocouple and RTD inputs, and (2) the TIMC includes internal 24V loop power for transmitters. The T1MC supports only thermocouples and RTDs. The TIMC is the “universal” version that also handles smart transmitters.

Q: What thermocouple types does the TIMC support?

A: The TIMC supports J, K, and T thermocouples. It does not support E, R, S, B, or N types. For those types, use a dedicated STBA, STBB, or STCA module.

Q: What RTD types does the TIMC support?

A: The TIMC supports Pt100 (α=0.00385) and Ni120 RTDs. It does not support Cu10. For Cu10 support, use a dedicated RTDB or RTDD module.

Q: Can I connect a 4-20 mA temperature transmitter directly to the TIMC?

A: Yes—the TIMC has internal 24V loop power, so you connect the two-wire transmitter directly to the input terminals. No external power supply is needed. The board’s 250Ω burden resistor converts the current to a voltage for measurement.

Q: I have a mix of thermocouples, RTDs, and transmitters in my cabinet. Can I use one TIMC board for all?

A: Yes—each channel is independently configurable. You can set Channel 1 as Type K thermocouple, Channel 2 as Pt100 RTD, Channel 3 as 4-20 mA transmitter, and so on. The configuration is done entirely in software—no hardware changes required.

Q: Is the TIMC a direct replacement for my existing dedicated modules?

A: Yes—mechanical and electrical compatibility is 100% with all Mark V temperature and analog input modules. Same form factor, same 96-pin DIN connector, same pinout, same field wiring terminal block. However, you must update the software configuration to match the sensor type for each channel. If you’re replacing a mixed set of modules with one TIMC, consolidate your configuration accordingly.

Q: What is the accuracy of the TIMC in 4-20 mA mode?

A: The TIMC’s 4-20 mA accuracy is ±0.05% of span, which translates to approximately ±0.008 mA. At a typical transmitter range of 0-100°C (4-20 mA), this is ±0.1°C accuracy, plus the transmitter’s own accuracy. This is comparable to dedicated analog input modules.

Q: Can the TIMC provide loop power for two-wire 4-20 mA transmitters?

A: Yes—the internal 24V loop power is available per channel. You don’t need an external power supply. This simplifies wiring and reduces cabinet complexity. The loop power is current-limited to protect against short circuits.

Q: What is the yellow LED on the TIMC for?

A: The yellow LED illuminates when any channel detects an open circuit (thermocouple or RTD break) or a 4-20 mA loop fault (wire break or transmitter failure). It provides a quick visual indication that a channel has a problem. The specific channel’s green LED will also turn off if the reading is invalid.

Q: Does the TIMC have conformal coating or extended temperature range?

A: Not in the standard version. The TIMC uses the standard 0°C to +60°C temperature rating with no conformal coating. If you need environmental protection, you would need a variant like DS3820TIMC1A1A (coated with gold-plated terminals) or DS3820TIMC1C1A (coated with extended temperature range). These variants exist but are rare. Contact us for availability.

Q: What is the update rate of the TIMC?

A: The TIMC scans all 8 channels at 10 Hz (100ms per full scan) regardless of sensor type. Each channel is sampled and converted to temperature or engineering units every 100ms. The scan rate is consistent across all input types.

Q: Can the TIMC be used for non-temperature 4-20 mA signals?

A: Yes—the TIMC’s 4-20 mA input can be scaled to any engineering units through the Mark V software. While designed for temperature transmitters, it can read any 4-20 mA process signal (pressure, flow, level) and scale it appropriately.

Q: What is the warranty on the TIMC?

A: Our standard warranty is 18 months from shipment, covering accuracy, channel integrity, and loop power functionality. If the board fails to maintain accuracy in any mode or the loop power supply fails, we replace it. The warranty does not cover physical damage or miswiring.

GE IC695CMU310
ALLEN BRADLEY 2711P-T12W22D9P
ABB NBRA-669C
ABB 216VC62A