On the display
The panel reads Circuit Breaker Does Not Open. The manual prints the message in this single form; no other variants are listed for it.
What it means
The message means that the flip dot is red, but the circuit breaker does not open. Everything the manual prescribes for this fault concerns the shunt trip, the wiring to and from it, the fuse feeding it and the 031-03958 board that drives it.
Why it appears
- The shunt trip is not latched correctly into the circuit breaker, so it cannot trip the breaker.
- Incorrect connections between the SHNT wire and the YEL wire to the shunt trip, or between the WHT wire from the shunt trip to the NTRL wire and back to the terminal block.
- The long HOT wire is not connected to the appropriate fuse, or the fuse is open.
- A failed 031-03958 board.
What to check
- Measure AC voltage between J2 pin 2 on the 031-03958 board and ground.
- If the reading is 120 V AC, connect a jumper between J2 pin 2 and J2 pin 3 on the 031-03958 board to trigger the shunt trip. 120 V AC is present at this point —
do not apply the jumper for more than a few seconds - damage to the shunt trip may occur
. - If the shunt trip triggers but the circuit breaker still does not open, make sure the shunt trip is installed according to the instructions provided. It may not be latched correctly into the circuit breaker and cannot trip it.
- If the shunt trip does not trigger, check the connections between the SHNT wire and the YEL wire to the shunt trip, and between the WHT wire from the shunt trip to the NTRL wire and back to the terminal block, per the connection diagram.
- If that wiring is correct, replace the 031-03958 board.
- If the voltage between J2 pin 2 and ground is not 120 V AC, make sure the long HOT wire is connected to the appropriate fuse and that the fuse is not open.
- If none of the above solves the problem, contact PTS.
Setpoints and thresholds
- Test threshold: 120 V AC between J2 pin 2 on the 031-03958 board and ground. A reading of 120 V AC leads to the jumper test on J2 pin 2 and J2 pin 3; any other reading leads to the long HOT wire and its fuse.
Questions engineers ask
What does 'Circuit Breaker Does Not Open' mean on a YORK YK chiller?
It means the flip dot is red, but the circuit breaker does not open. The manual traces the fault to the shunt trip, its wiring, the fuse feeding it or the 031-03958 board.
Why does my YORK YK show Circuit Breaker Does Not Open?
The manual lists four causes: a shunt trip not latched correctly into the circuit breaker, incorrect SHNT/YEL or WHT/NTRL wiring, a long HOT wire not connected to the appropriate fuse or an open fuse, or a failed 031-03958 board.
How do I test the shunt trip on a YORK YK?
Measure AC voltage between J2 pin 2 on the 031-03958 board and ground. If you read 120 V AC, jumper J2 pin 2 to J2 pin 3 for no more than a few seconds — applying the jumper longer can damage the shunt trip.
When should the 031-03958 board be replaced?
If the shunt trip does not trigger and the SHNT-to-YEL and WHT-to-NTRL wiring checks out correct against the connection diagram, the manual says to replace the 031-03958 board.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YK; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YK messages: fault codes · YORK YK documentation · YORK manuals