Nortec 132-3091 manual Max. Filling Time, No Current But High Water Sensor On, Cylinder Spent

2. Max. Filling Time

Symptom(s) Diagnosed: The fill valve has been “on” for a longer time than is normally required for non-zero current to flow between the electrodes or for water level in the cylinder to reach the high water sensor pin.

Probable Cause(s): Blocked drain due to blocked cylinder strainer or blocked drain valve preventing water from entering the cylinder. Drain valve leaking due to dirt in seal or powered by defective main PC board or powered by wiring error. High water sensor circuit not responding due to sensor plug not connected or defective high water sensor PC board or wiring error or defective main PC board. Water supply rate too low or zero due to too low pressure or line restriction or clogged built-in strainer. Too low supply water conductivity. DI (de-ionized) or RO (reverse osmosis) supply water has almost no conductivity. Measure conductivity and report findings to factory if suspected.

Response:

	UNIT STATUS LAMPS		REMOTE
			INDICATION
			(24 Vac to:)
UNIT	YELLOW	GREEN	61-20
CONTACTOR			“YELLOW”
OFF	ON	OFF	ON

NHB Explanation of Symptoms Without Automatic Shutdown

4. No Current But High Water Sensor On

Symptom(s) Diagnosed: High water level in the steam cylinder is detected, yet no current is detected in the steam cylinder.

Probable Cause(s): Sensor plug connected to wrong cylinder pin. High water sensor PC board defective (activates with no water). Main PC board defective (activates high water circuit without sensor PC board). Monitored leg of three phase power supply is dead. Main PC board defective (does not sense current when current is present in monitored leg).

5. Cylinder Spent

Symptom(s) Diagnosed: The high water sensor circuit is activated. Other criteria are used to distinguish cylinder spent from normal startup and diagnose the steam cylinder as spent, as previously described.

Probable Cause(s): As pure steam is produced from tap water, most minerals are drained by the auto-adaptive control system. However, it is inevitable that minerals will buildup on the electrodes and strainer inside the steam cylinder. It is unavoidable and the cylinder is intended to be disposable.

Unit Takes Self-Corrective Action: The humidifier continues to operate with gradually decreasing capacity, giving the user notice by responding as shown below.

Response :

	UNIT STATUS LAMPS		REMOTE
			INDICATION
			(24 Vac to:)
UNIT	YELLOW	GREEN	61-20
CONTACTOR			“YELLOW”
ON	ON	ON	ON

6. No Current But Humidistat Calling

Symptom(s) Diagnosed: For a few minutes, no current is detected in the steam cylinder, despite a demand for humidity. (Current is not expected to be zero when there is a demand for humidity.)

Probable Cause(s): Drain valve is leaking, so water never reaches the electrodes. Water supply is obstructed. Contactor is not activated. Supply water is “pure” without conductivity. Fill valve is blocked. Fill valve is not being activated. Supply water pressure is too low (less than 30 psig). Wrong orifice in fill valve. High duct static pressure blows back into the fill cup (via the steam line and empty cylinder) diverting the fill water to overflow. (Taking the steam hose off until some water gets into the cylinder solves this.)

6. Output Too Low

Symptom(s) Diagnosed: For a few minutes, current does not increase in the steam cylinder, despite the fill valve being activated. (Current is expected to increase soon after the fill valve is activated.)

Probable Cause(s): Drain valve is partially open, so fill rate maintains non-zero but non-increasing current. Continual overflow because high water sensor circuit did not respond to full cylinder. Supply water insufficiently conductive. Fill valve is partially restricted due to dirt, pinched supply line, or wrong orifice. Steam supply line is obstructed so back pressure causes continual overflow.

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