IC3600SLEH1G1B: GE Speedtronic Mark I-II Logic Element Card

The IC3600SLEH1G1B is a logic element card from General Electric's earliest Speedtronic turbine control platform, the Mark I / Mark II (IC3600) generation. These panels predate the microprocessor-based Mark IV and later systems: control and protection functions were built up from discrete, hardwired logic and analog cards plugged into a card nest. The SLEH is one of the logic building blocks in that architecture, and this listing covers the IC3600SLEH1G1B in clean, tested, used condition.

Where the SLEH Logic Element Card Sits in the Mark I-II Control Set

Reference descriptions of the SLEH describe a card that performs hardwired combinatorial logic. Each basic circuit is an 'OR' logic element gated by two 'AND' gates: when either AND gate sees all of its inputs at logic '1', the element's output goes to '1'. The card carries three of these circuits, and each one can drive a relay or driver output that closes a connection to a common terminal when its output is true. The inputs are high-level signals, and an OR-E expander input lets you extend a gate directly on the standard inputs by pairing the card with an expander such as the LLXA. There is also provision for tying the logic into external annunciators. Reference listings show the SLEH on a 51-pin edge connector.

In practice, cards like the SLEH implement the permissive, sequencing and protective logic strings that a Mark I-II turbine relies on the "if these conditions are all true, energize that output" decisions that were once wired in relays and later moved onto plug-in logic cards.

Diagnose Before You Buy: Is the Logic Card Really the Fault?

The most common mistake on a 40-plus-year-old Speedtronic panel is condemning a logic card for a problem that lives somewhere else. Because the SLEH output is simply the logical result of its inputs, an output that "won't come on" is very often the card correctly holding its output low because one of the AND-gate inputs is missing. Before ordering a replacement, work through the cheap checks first:

• Confirm the logic supply. Verify the regulated DC that feeds the logic nest (from the Speedtronic power-supply cards). A sagging rail makes good cards look dead.
• Check the inputs at the card, not just the output. If an upstream signal or companion card is not delivering a '1', the logic is behaving correctly. Trace the input that is missing.
• Reseat and clean the edge connector. Oxidized or contaminated gold fingers on the 51-pin connector are one of the single most frequent real faults on cards of this age. Reseating often restores a "failed" card.
• Test the downstream device. A relay or annunciator that will not pull in may be a bad coil or wiring, not the driver on the SLEH.
• Identify which of the three circuits is affected. Only one of the card's three circuits may be misbehaving; confirming which one keeps you from chasing the wrong signal.

Only when the inputs are present, the supply is good, the connector is clean and the downstream load is healthy does the logic card itself become the likely suspect.

Reading the IC3600SLEH1G1B Part Number and Revision

The number breaks down as the base function code IC3600SLEH, a variant group (1G here), and a trailing revision character the "B" in 1G1B. Related SLEH stock appears as IC3600SLEH1, IC3600SLEH1F and IC3600SLEH1G, and the final letter distinguishes hardware revisions and dash levels of the same card. When you order, match the entire string including the trailing revision to the card in your panel, rather than assuming any SLEH will drop in. For a walkthrough of how GE structures these codes, see our GE Speedtronic Part Number Decoder.

Companion and Related IC3600 Logic Cards

The SLEH is part of a broader set of Mark I-II logic and expander boards. The LLXA expander pairs with the SLEH's OR-E input to add gate terms, and other logic-element and interface cards populate the same nest. You can browse the wider range on our GE Mark I-II IC3600 Cards page, and see the full turbine-control lineup under GE Speedtronic Turbine Control Boards. If you are unsure which companion card a symptom points to, tell us the behavior and we can help narrow it down.

What to Send Us for an Accurate Quote

To make sure you receive the correct revision the first time, please include:

• The full part number with every suffix character (IC3600SLEH1G1B) and the revision as printed on the board.
• A clear photo of the card label and the component side.
• Your turbine model / frame and whether the unit is a Speedtronic Mark I or Mark II panel.
• Quantity required and how urgent the need is (planned spare versus unit-down).

Request a Quote for the IC3600SLEH1G1B

We supply the IC3600SLEH1G1B worldwide on DDP terms, and we welcome purchase orders. Send us your details and we will respond with a quote within 24 hours. Use the Request a Quote button to get started, and include the information above so we can confirm the exact revision and condition you need.

General Information about the Product
Part Number	IC3600SLEH1G1B Mark I-II IC3600
Description	IC3600SLEH1G1B By GE Speedtronic IC3600SLEH Logic Element Card
Condition	used Clean and Tested With 1 Year Warranty.