DS200PTCTG2BAA | GE Mark V 16-Channel CT Board

Description

Product Core Brief

• Model: DS200PTCTG2BAA
• Brand: General Electric (GE)
• Series: Mark V DS200
• Core Function: High-precision dual-bank current transformer termination with 16 channels
• Product Type: Current Transformer Termination Board (2 independent banks)
• Key Specs: 16 CT inputs | 5 A fixed | ±0.05% burden resistors | 2500 VAC isolation | 5 kV surge rating
• Condition: New Original / Factory surplus. Factory-sealed.

Product Introduction

The DS200PTCTG2BAA is a precision dual-bank current transformer termination board for GE’s Mark V DS200 series, used in Speedtronic turbine control systems. It integrates 16 channels of CT termination into a single board assembly with independent isolation between two 8-channel banks.

This is the highest-density precision CT termination board in the Mark V family. Each of the 16 channels uses a ±0.05% non-inductive burden resistor with 30 ppm/°C temperature coefficient. The two banks are isolated from each other at 2500 VAC, allowing connection to CT circuits with different ground references. Three-stage transient protection per channel meets IEEE C37.90 (5 kV surge). Locking shorting blocks with visual indicators are included for all 16 channels.

Key Technical Specifications

Key Selling Points & Differentiators

• 16 precision channels in one slot – Highest density CT termination for Mark V. Replaces two PTCTG1BAA boards and saves a rack slot. Ideal for generators with multiple CT sets (differential, metering, protection, neutral).
• ±0.05% burden resistors with 30 ppm/°C tempco – Each of the 16 resistors individually measured and certified. Meets revenue metering accuracy requirements across the full temperature range.
• True bank-to-bank isolation at 2500 VAC – Bank A and Bank B are galvanically isolated. Connect Bank A to generator CTs (floating at high potential) and Bank B to station service CTs (grounded). No ground loops, no common mode issues.
• Three-stage transient protection per channel (5 kV) – MOV + gas discharge tube + TVS. Independent per channel, not per bank. A surge on channel 3 does not affect channel 4. Tested to IEEE C37.90.
• Locking shorting blocks with red flag indicator – Each shorting block covers two channels (standard for three-phase CT grouping). Red flag visible when in “SHORT” position. Locking tab prevents vibration loosening. Rated for 20 A continuous.
• Non-inductive Ayrton-Perry burden resistors – Inductance under 0.2 µH. Phase shift variation with frequency under 0.05 degrees from 45 Hz to 65 Hz. Critical for harmonic analysis and protection relay coordination.
• Calibration certificate included for all 16 channels – NIST-traceable certificate showing actual burden resistance, phase shift, and output voltage at 1 A, 2 A, 3 A, 4 A, 5 A, 6 A for every channel.
• 2-year warranty – Covers any resistor drift, isolation breakdown, surge damage (within 5 kV rating), terminal damage, or shorting block failure.

Frequently Asked Questions (FAQ)

Q: What’s the difference between PTCTG2B, PTCTG2BA, and PTCTG2BAA?

The BAA is the only version suitable for revenue metering, generator differential protection (87G), or any application requiring NIST-traceable accuracy.

Q: Can I use this board for generator differential protection requiring matched CTs on both ends?
A: Yes. The ±0.05% resistor tolerance and <0.2° phase shift meet or exceed requirements for high-impedance differential schemes. However, you must use matched CTs on the generator neutral and line ends. The board itself adds negligible mismatch. For critical differential applications, we offer matched pair service: order two BAA boards (or one 2BAA and one 1BAA) with consecutive serial numbers. We match burden resistors across boards to within ±0.02%. Contact us for lead time.

Q: Why is there no 1 A option on the BAA?
A: The fixed 5 A design is intentional for utility and heavy industrial applications where 5 A CT secondaries are standard. Adding a 1 A jumper introduces potential failure points (wrong setting, corroded contacts). For 1 A CTs, use the PTCTG2ABC (selectable range with precision resistors) or PTCTG1ABC (single bank). The 2BAA is optimized for 5 A only.

Q: The board has 8 shorting blocks for 16 channels. How does that work?
A: Each shorting block covers two adjacent channels (channels 1+2, 3+4, 5+6, 7+8 for Bank A; same pattern for Bank B). This matches standard CT practice where three-phase CT sets are shorted in pairs. For independent shorting of a single channel, you would need different shorting blocks. We sell single-channel shorting blocks separately (part number ACC-SHORT-SINGLE). Contact us.

Q: What is the maximum cable length from the PTCTG2BAA to the analog input module?
A: The ribbon cable included is 1 meter (3.3 ft). For longer runs, use the direct screw terminal outputs (labeled “OUT+” and “OUT-” per channel) with twisted pair shielded cable. Maximum length: 100 meters for 0–1 VAC signal with 24 AWG shielded twisted pair. Beyond 100 meters, signal attenuation and noise pickup become problematic. For long runs, consider a signal conditioner (we sell the SCC-200 series).

Q: Can I mix CTs from different manufacturers on the same board?
A: Yes, electrically. The burden resistor presents a 0.1Ω load to any CT secondary. However, for applications requiring matched phase angles (e.g., directional protection, power metering), all CTs should be from the same manufacturer with identical accuracy class and burden rating. Mixing CTs can introduce phase shift mismatches of several degrees.

Q: The board is heavy (1.8 kg). Will the DIN rail hold it?
A: Yes, but with restrictions. Use steel DIN rail (35 mm x 7.5 mm, not aluminum). Install end clips on both sides (included). Do not use plastic DIN rail. For high-vibration environments, we recommend panel mounting using the four M4 screw holes instead of DIN rail. Panel mounting brackets are included.

Q: What cross-talk can I expect between channels?
A: Within the same bank: adjacent channels at 5 A produce less than 2 mV induced (0.4% of 0.5 V). Non-adjacent channels: less than 0.5 mV. Between banks (Bank A to Bank B): less than 1 mV induced on any channel when the opposite bank runs 5 A on all channels. For differential protection, leave one empty channel between high-current channels to reduce cross-talk below 0.5 mV.

Q: What QC tests are specific to the PTCTG2BAA?
A: Twelve tests, all documented with NIST-traceable data:

1. Visual: 20x magnification of all solder joints, especially burden resistors.
2. Burden resistance (all 16 channels): Kelvin four-wire measurement, 0.1Ω ±0.0005Ω. Logged per channel.
3. Bank-to-bank isolation: 3000 VAC for 5 seconds. Leakage <0.1 mA.
4. Input-to-output isolation per bank: 3000 VAC for 5 seconds. Leakage <0.1 mA.
5. Surge test per channel: 5 kV, 1.2/50 µs, 10 positive + 10 negative pulses. Output deviation <0.2%.
6. Accuracy sweep per channel (sample of 8 channels): 0.25 A to 6 A at 60 Hz. Error <0.1%.
7. Phase shift per channel (sample of 8 channels): <0.2 degrees at 5 A, 60 Hz.
8. Temperature coefficient (sample): −40°C, +25°C, +70°C. Drift <30 ppm/°C.
9. Cross-talk within bank: 5 A on channel 1, measure channel 2. <2 mV.
10. Cross-talk between banks: 5 A on all Bank A channels, measure all Bank B channels. <1 mV.
11. Overload: 30 A for 1 hour on all channels simultaneously. Resistor drift <0.05%. 150 A for 1 second—no damage.
12. Shorting block lock test per block: 50 cycles. Lock engages each time. Contact resistance <1 mΩ.
13. Thermal imaging: Full load 16 channels at 5 A for 4 hours. No hot spot >90°C.
14. Calibration certificate generation: NIST-traceable values for all 16 channels, laminated.

Q: What shipping protection for this heavy precision board?
A: Maximum protection. First: anti-static bag with humidity indicator. Second: custom-molded ESD foam cradle with cutouts for both terminal banks and the DIN connector. Third: hard plastic clamshell case with foam liner. Fourth: double-wall corrugated box with “PRECISION INSTRUMENT,” “CALIBRATION INCLUDED,” “HEAVY” (1.8 kg), and “DO NOT STACK” labels. Shock indicator label on outside. Each board ships individually. Calibration certificate laminated and attached to outside of clamshell. Shorting blocks shipped installed with foam inserts. Desiccant pack included.

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