i-Vu CCN

[chnrgr]

I have a place that is running a 4.2 version of the i-Vu. The programmer insists on setting the high and low setpoint at the same value.
i.e.
The target setpoint is 70 degrees. In turn he will adjust the Occupied Low Setpoint to 70 and Occupied High Setpoint to 70.

In my sense of logic that keeps the controls constantly adjusting and never settling out.

I would prefer if the target is 70 to set the low at 68 and the high at 72 giving a 4 degree band in the system.

These are clean rooms but we typically don't have a very tight spec we have to maintain.

Is there a good reason to set the high and low at the same number or am I just too old school?

[dlove]

there's nothing wrong with that if you want to try to maintain a fixed room temp but why not just override the stat and fix it to 70? but it don't make sense to me either.

I would be interested in his reason for this, because its a bit unusual. if you go into the unit config, you would have to change the min set point separation which is typically 2 and the set point adjustment range typically 4. and if your COV is .5 your box will be bouncing around. If the zone damper is part of many i would think it would cause issues.

IMO

[tkirkpatrick09]

Ive got the same system, same version. I keep it set low end 68 and high end 72 as you stated. Ive had having no band create nuisance calls especially when the customer can hear the unit constantly cycling and adjusting.