Description
Product Overview
The GE IS220PDIIH1B (circuit board assembly number 336A5026ADP1) is a 16-channel isolated discrete input pack from the GE Speedtronic Mark VIe control platform. It is part of the Packaged Discrete I/O family, and the front panel labels it plainly: DISCRETE IN.
This pack reads 24 VDC field contact signals — limit switches, relay auxiliaries, pushbuttons, interlock contacts — and publishes their state over dual redundant Ethernet to the turbine controller. It does not sit on a backplane. It mounts on a matched terminal board in the field, and all communication happens over IONet.
That distributed architecture is the whole design point. Field wiring lands on a nearby terminal board, the pack snaps on top, and only two Ethernet cables run back to the rack. Marshalling cabinets shrink, home runs shorten, and a failed pack swaps out without touching the field wiring.
The H1B suffix marks the second-generation hardware revision. This unit ships as rev C on the label, and it carries UL Class 1 Division 2 approval for hazardous-area mounting.
IS220PDIIH1B 336A5026ADP1
Core Product Features
- Sixteen optically isolated 24 VDC discrete input channels read dry-contact and wet-contact field signals from switches, contacts and auxiliary relays.
- Each channel has its own LED on the front panel, numbered 1 through 16, so a technician can walk the rack and see contact state at a glance.
- Dual 10/100 Mbps Ethernet ports (ENET1 and ENET2) carry redundant IONet traffic, so a broken cable does not drop the channel.
- The pack is self-contained: on-board processor, signal conditioning, isolation and network stack all in one sealed enclosure.
- UL Class 1 Division 2 certification for Groups A, B, C and D allows mounting in classified areas without additional purging.
- Wide 28 VDC nominal supply with 0.15 A draw keeps power loading low on distributed I/O drops.
- Input contact range of 10 to 32 VDC tolerates long cable voltage drop and unstable field supply without false state changes.
- Mounts on a matched ISx0ySDIIH1A terminal board; the pack itself pulls off while field wiring stays seated.
- Conformal-coated electronics suit the dust, humidity and vibration of turbine halls and offshore platforms.
Technical Specifications
| Item | Specification |
|---|---|
| Ordering model | IS220PDIIH1B |
| Assembly number | 336A5026ADP1 |
| Hardware revision | rev C (H1B family) |
| Product type | Packaged discrete input pack, isolated |
| Compatible platform | GE Speedtronic Mark VIe |
| Input channels | 16, individual LEDs per channel |
| Signal type | 24 VDC contact (dry or wet) |
| Input contact range | 10 VDC to 32 VDC |
| Supply voltage | 28 VDC nominal |
| Supply current | 0.15 A |
| Isolation | Optical, channel group to network |
| Network | Dual 10/100 Mbps Ethernet, IONet redundant |
| Terminal board | ISx0ySDIIH1A (required) |
| Operating temperature | -30°C to +65°C |
| Dimensions | 86.2 mm × 149 mm × 121 mm |
| Weight | 0.5 kg |
| Enclosure rating | IP20, sealed plastic housing |
| Hazardous area | UL Class 1 Div 2, Groups A–D, T4C |
| Configuration | ToolboxST engineering software |
| Certifications | UL, cULus, CE, ATEX/IECEx pending family |
| Origin | United States |
Some distributor pages describe this pack as a combined input/output unit. The front-panel marking and the internal schematic both confirm it is input-only — sixteen channels, no relay outputs. Treat the 16-channel input figure as the working baseline and verify against the terminal board part number when ordering spares.
IS220PDIIH1B 336A5026ADP1
Product Details and Application Fields
Product Details
Pack and terminal board split. The PDII pack is the electronics. The SDIIH1A terminal board carries the field wiring screw terminals. When a pack fails, you loosen two screws and lift the pack off. The field wires do not move, which is why maintenance teams like this architecture.
Signal path. A contact closes on the field side, voltage passes through the terminal board to the pack’s input circuit, opto-isolation separates the field from the network side, and the on-board processor publishes the new state over IONet. Latency stays in the low-millisecond range, fast enough for interlock logic.
Dual Ethernet design. ENET1 and ENET2 are not separate networks for different purposes. They form a redundant pair, so a single broken cable or switch fault does not interrupt I/O scanning. The pack expects both links to be live; a single-port install will flag a fault.
Power distribution. The 28 VDC supply comes from the plant’s I/O pack power rail, not from the field contacts. Because the pack supplies its own wetting voltage, dry contacts work without external power at the field end.
Hazardous area mounting. The Class 1 Div 2 rating means the pack can live in the same cabinet as gas processing equipment, as long as the atmosphere is not continuously explosive. This eliminates a separate purged enclosure for many installations.
Revision context. H1B is the second-generation Mark VIe I/O pack. Earlier H1A packs remain in service and are backward-compatible on the network, but the terminal board and internal electronics differ. Mixing revisions is allowed on IONet, but always confirm the terminal board matches the pack revision before ordering.
Application Fields
- Turbine protective interlock status inputs: trip relay auxiliaries, overspeed test contacts, vibration monitor contacts
- Lube oil and hydraulic system pressure switch feedback on gas and steam turbine packages
- Boiler and burner management discrete inputs in thermal power generation
- Emergency shutdown pushbutton and ESD relay status monitoring in oil, gas and refining facilities
- Mark VIe retrofit projects replacing legacy centralised DI racks with distributed IONet packs
- LNG terminals, offshore platforms and compressor stations where Div 2 area certification is required
- Fleet standardisation across multi-unit plants that stock a single spare pack number
IS220PDIIH1B 336A5026ADP1
Related Model Recommendations
- IS220PDIAH1B — 16-channel discrete input pack from the same H1B generation, for non-isolated or standard-density DI applications.
- IS220PDOAH1B — companion discrete output pack, used alongside PDIIH1B for solenoid and indicator control on the same IONet drop.
- ISx0ySDIIH1A — matching terminal board required for field wiring termination; the pack does not function without it.
- IS215UCVEH2AE — Mark VIe control engine that collects PDII input states over IONet and runs the turbine protection and sequence logic.
