Hi and welcome.
I would set a boolean property in the msg, then use that to filter messages with the filter/rbe node.
so when over 1500 msg.pass would be true, then filter node will allow msg to pass once until msg.pass became false.
e.g.
[{"id":"1d88c4fe.66b62b","type":"inject","z":"b779de97.b1b46","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"1000","payloadType":"num","x":220,"y":4020,"wires":[["779122e.80aca5c"]]},{"id":"779122e.80aca5c","type":"change","z":"b779de97.b1b46","name":"","rules":[{"t":"set","p":"pass","pt":"msg","to":"$$.payload > 1500","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":410,"y":4020,"wires":[["76a0a2c8.3a55fc"]]},{"id":"96b6e747.44ec1","type":"inject","z":"b779de97.b1b46","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"2000","payloadType":"num","x":230,"y":4060,"wires":[["779122e.80aca5c"]]},{"id":"76a0a2c8.3a55fc","type":"rbe","z":"b779de97.b1b46","name":"","func":"rbe","gap":"","start":"","inout":"out","septopics":true,"property":"pass","x":590,"y":4020,"wires":[["d147b3bb.224868"]]},{"id":"d147b3bb.224868","type":"debug","z":"b779de97.b1b46","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":730,"y":4000,"wires":[]}]