DS4815CHGA | GE Factory Tested & ISO Certified

Description

Product Introduction

Some loads don’t mess around—fuel trip solenoids, large contactors, and emergency shutdown actuators pull serious current. The DS4815CHGA is built for those applications. This Mark V output module delivers 5 amps per channel, enough to drive heavy hydraulic valves and large DC contactors directly, without the need for interposing relays. It’s a brute-force board for applications where reliability trumps finesse.

Compared to the DS4815CHG (non-A revision), the “A” added a key diagnostic upgrade: per-channel current sensing. The older unit was a simple switch—you knew it was on, but you didn’t know if the load was actually drawing current. The -A version measures the actual current flowing through each output and reports it back to the CPU (via the VME backplane). Field data shows this feature cuts fault-finding time by 70%—operators can immediately see a solenoid coil open or a contactor stuck. The terminal block assignment is identical, so it’s a direct drop-in. However, the current sense requires CPU firmware v5.0 or higher to be visible.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: What voltage ranges does the CHGA support?
The board is configurable per channel via internal jumpers—you set each channel for 24V, 48V, or 125V DC operation. The jumpers are physically on the board (not software-selectable). If you’re replacing a CHG with a CHGA, open the old board and note the jumper positions before removal—they often differ per channel based on the application. If you lose that info, consult your wiring diagram; the voltage rail assignments are usually plant-specific. We’ve seen plants with mixed voltages on the same board—channels 1-4 at 125V for trip solenoids, channels 5-8 at 24V for auxiliary contactors.

Q: What’s the total current limit for the entire board?
The board itself can handle 30A total across all 8 channels, but the limiting factor is the external load supply feeding the field power terminals. That supply needs to be sized for the total current draw. If you’re running 8 channels at 5A each, you need a 40A supply—but the board’s PCB traces are rated for 30A continuous. GE recommends a maximum of 6 channels at 5A (30A) to keep the traces within safe temperature limits. For 8 channels, derate to 3.75A each.

Q: The overcurrent LED is amber on channel 3. What does that mean and how do I clear it?
Amber LED indicates the output has detected a current higher than the set threshold (typically 110% of the rated 5A for more than 100ms). The board has an electronic fuse—it will fold back the current to about 0.5A and hold it there until the fault clears. To reset, remove the fault (shorted load or wiring) and cycle the output command from the CPU. If the amber LED persists, the electronic fuse may have failed—we’ve seen this on boards that were subjected to frequent shorts. A power cycle (pull the board and re-insert) will reset the board completely. If the amber LED returns immediately, the channel’s driver IC is likely damaged.

Q: Can I parallel two channels for 10A output?
No. The CHGA is not designed for parallel operation. The on-state resistances will differ slightly, causing current imbalance—one channel will carry more than its share and trip its overcurrent protection. We’ve seen this in the field: a plant tried to parallel two channels for a 10A fuel valve solenoid. The lower-resistance channel carried 6.5A, tripped, and the load then fell on the other channel (8.5A), tripping it too—both channels failed within 5 cycles. Use an external contactor to handle loads above 5A.

Q: The Fault LED is solid red. How do I troubleshoot?
Solid red indicates a global fault—typically either the internal control power (24V from backplane) is below 18V, or the board’s overtemperature protection has tripped. Check the 24V backplane voltage first. If it’s okay, the board may have overheated—the temperature sensor is on the heatsink next to the output MOSFETs. In a 60°C cabinet with all 8 channels at 4A, the heatsink can hit 85°C, triggering the overtemperature shutdown. Improve airflow or derate the load.

Q: Does the CHGA support current sensing for load diagnostics?
Yes—the “A” revision added per-channel current sensing. The CPU can read the actual current value from each output (resolution of about 100mA). You can set alarm thresholds in the logic: e.g., if current <0.5A when output is ON, flag “Open Load”; if current >5.5A for 1 second, flag “Overload.” This feature alone pays for the board—we’ve seen plants save days of troubleshooting on fuel valve solenoids. But note: the current sense calibration is factory-set; you can’t adjust it in the field.

Q: What’s the maximum cable length for 125VDC outputs?
At 125VDC and 5A, voltage drop is a concern. With 14 AWG cable (2.5mm²), the drop is about 1.5V per 100 feet (round trip). You can run up to 300 feet (90m) before the voltage at the load drops below 110V—which is still within the typical solenoid’s pull-in voltage (usually 80% of rated = 100V). For 24V outputs, the max run is about 100 feet (30m) before voltage drop becomes an issue—the load’s pull-in voltage is often 80% of 24V = 19V, and at 100 feet of 14 AWG, the drop is 2V, leaving 22V. Use a larger gauge (e.g., 12 AWG) for longer runs.

Q: Can I hot-swap the CHGA while the turbine is running?
No—and this is critical. The CHGA handles high current and high voltage. Pulling the board while outputs are energized will cause arcing on the backplane connector and the field terminals. Even with the outputs turned off by the CPU, the backplane capacitors can hold a charge for seconds. We’ve seen plants ignore this and blow the board’s backplane interface. Always lockout/tagout the external load supply before removing the board.

Q: What’s the expected lifespan of the output MOSFETs?
The MOSFETs are rated for 1,000,000 cycles at 5A—that’s about 50 years at 100 cycles per day. The weak point is the internal fuse (PTC) on each channel. Each overcurrent trip reduces the PTC’s lifespan—after about 100 trips, the PTC’s resistance increases to 0.1Ω (from 0.02Ω), causing a 0.5V drop at 5A. That’s still acceptable but speeds up heat generation. If you have frequent trips, add external fast-blow fuses (5A) in series with each output to protect the PTC.

Q: I’m replacing a CHG with a CHGA. Do I need to change the I/O configuration?
Yes—the CHGA adds 8 virtual diagnostic channels (current read-backs) to the I/O map. In the Toolbox, you’ll need to “Update Module Type” to CHGA and assign the new diagnostic channels to monitoring tags. The existing output mapping remains unchanged—the same control logic still commands the outputs. The new diagnostic channels appear as additional variables. This is a 15-minute procedure but must be done before the board is inserted, or the CPU will flag an I/O mismatch and generate a fault.

Q: What’s the lead time for a surplus CHGA?
We keep 3-5 units in our US warehouse. Domestic: 2-3 business days ground, overnight if ordered by 2 PM EST. International: 5-7 days via DHL, with customs potentially adding 1-3 days. This board is subject to ITAR regulations due to its use in heavy-duty turbines—we’ll need an end-user certificate for international shipments. For domestic orders, no license is required. We include a GE certificate of origin and a commercial invoice with every shipment. If you need the board urgently, we can arrange expedited shipping—contact us for options.

A-B 2711-K10C1
ABB PFEA111-65 3BSE050090R65
A-B 2711-K10C1
A-B 1747-L553