Error: Script execution timed out after 30000ms

I am trying to do some load testing. I am using newman in nodejs.
In my script I have async.parallel to execute several collections in parallel. Then repeat set of parallel excution every 5 sec. In each run I have the following options:

        collection: require('./collection.json'),
        environment: require('./environment.json'),
         timeoutRequest : 0, // infinite timeout
        delayRequest: 1000, // ms
        iterationCount: 5

Tha main loop looks like:

async function sleep(ms) {return new Promise(done => setTimeout(() => done(), ms));}

async function orchestrator() {

for(let j=0; j < cycles; j++)

        function (err, results) 
            if (err) { throw err; }
    await sleep(5000);

The last 3 lines of output are:

Process exited with code 1

I set cycles to 500. All goes well for 70+ cycles but then I get the error mentioned.

Have you a solution or some work around I can do?