On the display
The OptiView Control Center of the YORK YMC2 shows WARNING - UPS - BATTERY NOT CONNECTED on its display. The manual lists this message among the warning messages, and it appears in only this one wording — no variants are given.
What it means
This is an auto reset warning that tells you the control has read the battery voltage pattern of a UPS battery that is not connected. It is built purely from voltage measurements: the minimum and maximum Battery Voltage that occurs within each 10 second window is stored, and at the end of each window the difference between them is judged. A difference greater than 0.5 V increases the Battery Disconnected Counter; a difference less than 0.5 V resets the counter to 0. The warning is set when the Battery Disconnected Counter >= 4 — the manual's stated intent is for 4 consecutive 10 second windows to see battery voltage fluctuations.
Why it appears
- Battery voltage fluctuation: within a 10 second window the difference between the minimum and maximum battery voltage is greater than 0.5 V, which increases the Battery Disconnected Counter.
- 4 fluctuating windows in a row: once the Battery Disconnected Counter >= 4 the warning is set. This fluctuation pattern is the only cause the manual gives — no battery, wiring or UPS checks are listed for this message.
Setpoints and thresholds
- 10 second window — the period over which the minimum and maximum Battery Voltage are stored and then compared.
- 0.5 V — a window whose difference is greater than 0.5 V increases the Battery Disconnected Counter; a difference less than 0.5 V resets the counter to 0.
- Battery Disconnected Counter >= 4 — the level at which the warning is set.
- 60 continuous seconds — how long the counter must stay at 0 for the warning to be released.
Reset and restart
No manual reset is described for this message — it is an auto reset warning. The counter is reset to 0 at the end of any 10 second window in which the battery voltage differs by less than 0.5 V between minimum and maximum, and It is released when the Battery Disconnected Counter is 0 for 60 continuous seconds.
In practice: once the battery voltage stops fluctuating by more than 0.5 V per 10 second window, the counter returns to 0 and the warning clears by itself after 60 continuous seconds.
Questions engineers ask
What does WARNING - UPS - BATTERY NOT CONNECTED mean on a YORK YMC2?
It is an auto reset warning that is set when the Battery Disconnected Counter >= 4 — after 4 consecutive 10 second windows in which the battery voltage swung more than 0.5 V between its minimum and maximum.
How does the YMC2 decide that the UPS battery is not connected?
The control stores the minimum and maximum Battery Voltage of each 10 second window. A difference greater than 0.5 V increases the Battery Disconnected Counter, a difference less than 0.5 V resets it to 0, and a counter value >= 4 sets the warning.
How do I clear the UPS battery not connected warning?
No reset action is needed — it is an auto reset warning. As soon as a 10 second window shows less than 0.5 V of swing the counter returns to 0, and once it has been 0 for 60 continuous seconds the warning is released.
What battery voltage fluctuation sets the warning?
A swing greater than 0.5 V between minimum and maximum battery voltage within a single 10 second window. 4 consecutive such windows take the Battery Disconnected Counter to >= 4 and set the message.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YMC2; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YMC2 messages: fault codes · YORK YMC2 documentation · YORK manuals