Error messages in making a binary sensors

I got this error messages when I run this binary sensors

Logger: homeassistant.components.threshold.binary_sensor
Source: components/threshold/binary_sensor.py:108
Integration: threshold ([documentation](https://www.home-assistant.io/integrations/threshold), [issues](https://github.com/home-assistant/home-assistant/issues?q=is%3Aissue+is%3Aopen+label%3A%22integration%3A+threshold%22))
First occurred: October 19, 2020, 7:51:48 PM (11 occurrences)
Last logged: 6:07:59 PM

State is not numerical

My code

binary_sensor:
  - platform: threshold
    entity_id: sensor.ac_daikin_current
    upper: 400
    name: Real AC Daikin Status

here is my sensor.ac_daikin_current

![Screen Shot 2020-10-20 at 7.11.52 PM|406x257(upload://9hr5zBh0TMde3QsKoKq7EQDvEAR.png)

Help…