AdiaPure

Concepts

The handful of ideas you need in order to configure and troubleshoot an AdiaPure unit.

This page explains the handful of ideas you need in order to configure and troubleshoot an AdiaPure unit.

Demand

Demand is how much water the unit should put into the air, expressed as a percentage from 0 % to 100 %. The controller can take the demand from six different sources, chosen with the Demand input mode setting:

SourceHow it is measured
0-10V demandThe voltage on the demand input, 0 V = 0 %, 10 V = 100 %
4-20mA demandThe current on the demand input, 4 mA = 0 %, 20 mA = 100 %
On/OffThe demand input is either 0 % or 100 %
External demand registerA percentage written to a register over Modbus or BACnet
Return humidity voltageA 0–10 V return-air humidity signal, compared with a setpoint
Return humidity currentA 4–20 mA return-air humidity signal, compared with a setpoint

In the two return-humidity modes the demand is not read directly. Instead the controller runs a closed loop: it compares the measured return humidity with the setpoint you gave it and derives the demand from the difference. The loop runs on a fixed cycle (PWM period, 10 s by default).

The limiter

The high-limit transmitter is a humidity sensor in the air leaving the humidifier. Its job is to stop the unit from humidifying so hard that water condenses inside the unit.

When the measured output humidity rises above the Highlimit transmitter threshold (60 % by default), the controller subtracts a penalty from the demand:

penalty       = (measured output humidity - threshold) × gain
final demand  = max(0, demand - penalty)

The Highlimit transmitter gain (7.0 by default) sets how sharply the output is cut back. With the default gain, every 1 % of humidity above the threshold removes 7 % of the demand.

Two values are shown for the demand so you can see the limiter working:

Web interface labelMeaning
Demand (pre-limiter)The demand as it arrived
Demand (post-limiter)The demand after the limiter has had its say

On the screen, the banner Output reduced due to Highlimit transmitter appears while the limiter is active.

Valves and the duty cycle

The unit has four atomisation valves. They are opened in stages, and each stage is controlled by pulse-width modulation: the valve is opened and closed repeatedly within a cycle, and the fraction of the cycle it stays open is the duty cycle.

Each valve has four settings:

SettingMeaning
level_lowThe demand at which this valve starts to open
level_highThe demand at which this valve is fully open
pwm_startThe smallest duty cycle this valve uses once it is active
pwm_endThe largest duty cycle this valve uses

Out of the box only the first two valves are enabled:

Valvelevel_lowlevel_highEffect
Valve 110 %50 %Starts working at 10 % demand, fully open at 50 %
Valve 250 %100 %Starts working at 50 % demand, fully open at 100 %
Valve 30 %0 %Disabled (the low and high levels are equal)
Valve 40 %0 %Disabled

A valve whose level_low is equal to or higher than its level_high never opens. That is how you disable a stage, and it is also how the flushing routine knows to skip it.

The pump runs whenever the demand after the limiter is above zero. It is not switched off and on again for every cycle: if it would only be off for less than a second, the controller leaves it running.

Modes

The controller has three modes. You select them on the screen and in the web interface, and they are also readable and writable over the fieldbus.

ModeWhat it does
STANDBYNothing runs. The pump is off and the valves are closed. This is the mode the unit starts in.
AUTOMATICThe unit follows the demand, but only when every enable condition is met.
TESTThe unit runs at a fixed test demand, ignoring the enable conditions. It returns to STANDBY on its own when the test duration is over.

What has to be true to run in AUTOMATIC

If any of these conditions fails while the unit is in AUTOMATIC, the pump and the valves stop immediately. The screen shows which one is missing in the banner, for example Waiting: Airflow.

In TEST mode the unit runs regardless of the master enable, the hygrostat, the airflow and the alarms.

Mode changes

The test duration defaults to 1800 seconds (30 minutes). After that the unit returns to STANDBY on its own.

Flushing

Atomisation valves must be flushed regularly, otherwise the nozzles clog and the water quality degrades. The controller runs a flush routine:

  1. the pump stops and all atomisation valves close;
  2. the flush drain valve opens;
  3. the controller waits 3 seconds;
  4. each enabled valve is opened in turn for Flush duration (30 seconds by default), with a 3-second drain wait after each one;
  5. the flush drain valve closes.

A flush is started when:

  • the Flush interval has elapsed (24 hours by default);
  • the water temperature or the conductivity has gone out of range;
  • somebody asks for one (see Using the product).

A flush that is interrupted by an alarm closes all the atomisation valves first and leaves the flush drain valve open for 3 more seconds so the water can drain away.

Valves that are disabled (equal low and high levels) are skipped during the flush.

Alarms, and how they escalate

Alarms come in two flavours.

Transient alarms describe a condition that is happening right now. They clear automatically as soon as the condition goes away:

  • Water Temperature Too High
  • Conductivity High
  • Inlet Pressure Too Low
  • Pump Pressure Too Low
  • Motor Temperature High
  • Board Temperature High
  • Conductivity Sensor Fault

Sticky alarms stay until you acknowledge them:

  • Water Temperature High — the water stayed too hot for long enough
  • Conductivity After Flush — the water stayed too conductive for long enough
  • Water Pressure Low — the inlet pressure stayed too low for long enough
  • Water Pressure High — the pump pressure stayed too low for long enough
  • Water Leak Detected
  • No Motor Drive
  • Maintenance Required
  • Input Signal Error

A transient alarm turns into its sticky counterpart in two ways:

  • It persists. Water temperature and conductivity become sticky after 2 minutes; the two pressure alarms become sticky after 30 minutes.
  • It keeps flapping. Water temperature and conductivity become sticky after 3 trips in one hour; the two pressure alarms become sticky after 10 trips in one hour.

That way a sensor that is only briefly out of range does not force an operator to acknowledge anything, but a genuinely broken sensor does.

Two alarms never clear by themselves at all: Water Leak Detected and Input Signal Error. Both need a manual reset.

See Status and alarms for the full list.

Maintenance countdown

The controller counts two things:

  • Pump hours — the number of hours the pump motor has been running.
  • Maintenance countdown — a one-year countdown to the next maintenance.

When the countdown reaches zero, or when more than 2000 pump hours have passed since the last maintenance, the alarm Maintenance Required is raised.

Acknowledging the maintenance (writing the maintenance register) resets the pump-hours counter and restarts the one-year countdown. The web interface shows the remaining pump hours and the remaining countdown in the Maintenance card.

Relay outputs

Four relay outputs report the state of the unit:

OutputActive when
StatusThere is a demand and the demand controller is running
AlarmAt least one alarm is active
Aux 1Any alarm in the Aux 1 alarm mask is active
Aux 2Any alarm in the Aux 2 alarm mask is active

Each output can be set to rest open (Normally Open) or rest closed (Normally Closed). With the default Normally Open setting the contact is open while the output is inactive and closed while it is active; with Normally Closed it is the other way round.

The valve lock

Only one part of the system may command the valves at a time. When the flushing routine runs it takes the valve lock, and the normal demand controller waits until it is released. You can see the lock state as Valve lock over the fieldbus.

Next steps

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