Nortec Comprehensive Guide to Humidifier Manuals and Error Codes

9. Phase Interrupt - Error 8 (NHMC only)

Symptom(s) Diagnosed: The 24 VAC to the main PCB, across terminals 44 and 46 is interrupted.

Probable Cause(s):

a)A wiring problem leading to an interruption of the 24 VAC to terminals 44 and 46 of the main PCB.

b)A problem with the main PCB.

Corrective Action:

1.With the unit switched on, measure across terminals 44 and 46 of the main PCB for 24 VAC. If not present, find the cause of interruption. If present, the problem is with the main PCB.

Response: See Figure #2, NHMC System Messages

10. Cyl. Lifespan End - Error 9

Symptom(s) Diagnosed: The criteria for diagnosing Cylinder Spent - Error 4 has expired and cylinder has not been replaced. Humidifier has shut down to avoid unsafe operation.

Probable Cause(s): Refer to Error 4.

Corrective Action: Refer to Error 4.

Response: See Figure #2, NHMC/NHP System Messages.

Troubleshooting Dual Cylinder Units

Double units, NHMC-150 and 200, are two circuits in one cabinet sharing one LCD display. A ribbon cable between the RS232 ports links the two circuits. The left circuit is the master. [1] on the display means left side. [2] on the display means right side.

Refer to double unit operation on in the NHMC Installation and Operation Manual.

When a fault occurs on the right side of a double unit, both sets of lamps (and remote relays) will come on indicating that a fault has occurred. The left side (master) will display its own faults as well.

The LCD will indicate which fault has occurred and on which side of the unit, [1] or [2]. The side not faulted will continue to operate as usual.

The side which has shut down on fault can be treated as a single circuit using the same troubleshooting guidelines as previously described.

NHB

The NHB checks the status of the electrical circuits to the fill valve, drain valve, primary voltage contactor, high water sensor and steam cylinder. The manual capacity setting, if reduced, is taken into consideration. When problem symptoms are found, the NHB will, if necessary, respond by shutting itself down.

The NHB communicates its findings to the user by way of the unit’s status lamps and a 24 Vac (maximum 100 mA maximum) signal sent to the terminal strip for optional external remote indication.

The signal for remote indication comes in response to the following symptoms. In each case, the NHB shuts itself down. The green status lamp goes off, but the yellow status lamp (and remote fault relay) remain on.

NHB Explanation of Automatic Shutdowns

1. Excess Current

Symptom(s) Diagnosed: Current in steam cylinder increases beyond the fill off and emergency drain on triggers. Current reaches 150% of FLA (i.e. 134% of fill off rated amps; i.e. 134% of amps on spec. label) for 1 second.

Probable Cause(s): Blocked drain due to blocked cylinder strainer or blocked drain valve or blocked external drain line. No power to drain valve at emergency drain on trigger. Power remains on fill valve at fill off trigger. Wrong steam cylinder (too conductive). Wrong fill valve (orifice too big). Wrong supply voltage (too high). Supply water too conductive. Contained water too conductive. 100% softened supply water is often too conductive. Measure conductivity and report findings to factory if suspected. Mineral bridge between electrodes.

Unit Takes Self-Corrective Action: It has already tried to control current with fill off and emergency drain on triggers. It then responds as shown below.

Response:

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

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