🚦 Typical Run Chain (qualifying a start)

Here’s the simplified ladder of what has to be true for the car to pick brake/main and move:

Power Feed →
60N (Run/Stop switches closed) →
40A (Gate closed & proved) →
41 (All hatch door locks made) →
43A (Door Close Prove) →
[Direction sequence: 32s picked by 1 or 2 demand] →
BR/Main Contactor coil →
Car runs

How it behaves:

MG Run (5) is up once machine is ready.

When a call is registered (100s/200s/300s), either 1 (Up Demand) or 2 (Down Demand) picks.

That pulls the appropriate 32s (directional starter).

But 32s can only hand off to brake/main if the “door-closed chain” is made:

60N + 40A + 41 + 43A.

If 43/43A never makes, the timer kicks → doors recycle (your symptom).

Once motion starts, MV/MVA seal in and traffic logic clears door commands.

👉 This gives you a working cheat sheet + run chain.
Would you like me to make this into a one-page printable PDF with the table and the ladder diagram so you can tape it inside the controller?

You said:
So back to the original problem, what do you think it is?
ChatGPT said:
Thought for 22s

Short answer: it’s almost certainly a missing door‑closed prove in the run chain—i.e., your 43A/DCL path never makes solid—so the controller times out, reopens, and retries. or a bouncy gate 40/40A.

Here’s how I’d pin it down fast, no prints needed:

What to watch (in order)

43 (Door Close) coil

Does 43 energize while the doors close?

If no → chase the close command (44 dropping, close limit not made, door motor limit).

If yes, go to #2.

43A (Door‑closed prove) contact

Meter across 43A during full close. You want 0 V (contact closed).

If it never goes to 0 V (or flickers), that’s your recycle.

Common causes: misadjusted close limit, worn cam/roller, bad 43 aux blade, carbon on tips, or high‑resistance crimp.

40/40A (Gate) and 41 (Hatch locks)

Both should be picked at full close; meter across 40A and 41 (look for 0 V).

Gently flex the gate tongue—if 40A bounces, the car will never qualify a start even if 43 is up.


Run chain at the brake coil (most decisive)

While it’s “waiting to go,” put your meter on the brake coil or the first motion device (PM/BR).

If there’s no coil voltage, walk back through the series: 60N → 40A → 41 → 43A (→ DZ if used) → 32s. The first spot you see full line is your open.

Why “popping a lock” didn’t drop anything

On a lot of these, the start‑permit doesn’t use the raw lock string directly; it uses the door‑closed prove derived from the door operator (your 43A/DCL). So popping one lock won’t drop anything because the run chain was already open upstream at 43A—hence no visible change.

My bet (ordered)

43A/DCL not making (misadjusted close limit or weak/burnt 43 aux)

Gate 40A bounce (tongue/keeper just shy—closes, then relaxes)


If you want, tell me the exact behavior of 43, 43A, 40A, and 41 at “doors fully closed,” and I’ll point to the exact contact to tweak.