Nortec Steam Humidifiers manual Procedures and Terms Used Diagnosing

PROCEDURES AND TERMS USED IN

DIAGNOSING

PRINCIPLE OF OPERATION

The conductivity of the water within the cylinder must be controlled in order for the humidifier to function properly. The fill and drain rates must be maintained. Filling too quickly can cause over-amping and automatic shutdown or blown fuses. Filling too slowly can cause insufficient steam output and foaming. Water supply pressure should be between 25 and 110 psig. Draining too slowly can cause over-concentration and malfunction due to foaming. These are just some examples of what can go wrong if the fill and drain rates are not maintained.

FILL RATE

Fill rates of suspect units should be checked. Fill rates should measure nominally at 1" to 1-1/2" of vertical rise in water level in the cylinder in one minute.

Clogged fill valve will cause lower fill rate. The fill valve strainer is removable and can be cleaned.

DRAIN TIME

Manual drain time of a half full cylinder takes approximately 25 seconds.

If time measurements are longer, repeat with the external drain disconnected (and draining into a pail) to verify that the external drain is impeding flow. If it still does not drain, check for a clogged strainer or drain.

A clogged strainer or drain valve will cause shortened cylinder life. Determine what caused the strainer or drain valve to clog in the first place.

Do not assume that if a strainer and/or drain valve is clogged that it is to blame. If the external drain has been impeding flow then waste accumulates resulting in a clogged strainer or clogged drain.

Clean the drain valve and install a fresh cylinder. Then measure the manual drain time with and without the external drain connected. Is the external drain impeding flow? NORTEC recommends an open external drain line. See the Installation section of this manual.

RATED AMPERS

This refers to amps listed on the humidifier specification label.

SHORT CYCLING

When the ‘on time’ of the humidifier is less than ten minutes upon a call for humidity. To correct short cycling, all humidifiers have a capacity adjustment which allows the output of the humidifier to be reduced as low as 25% of rated output, thus extending the ‘on time’ required to maintain output. Excessive short cycling may cause higher water conductivity (mineral content) than designed for the unit.

FOAMING

A phenomenon which can occur in water when impurities, already in the water, reach an excess concentration as result of boiling away pure water and the continued boiling action agitating the contained water. The humidifier electronics are designed to prevent this occurrence although in extreme cases water will foam with little concentration, making it necessary to have the drain time of the water, contained in the cylinder, increased. Foaming is normally caused by short cycling, a restricted drain, or back pressure. The foam, generated in these instances, is conductive and may lead to a false full cylinder indication if the level of the foam approaches the top of the cylinder.

BACKPRESSURE

Restriction of steam flow caused by improperly sloped steam lines, elbows changing the direction of the steam flow from horizontal to vertical without a condensate drain leg, and any plumbing detail allowing the accumulation of condensate.

MONITORED LEG

Refers to the primary wire, to the cylinder, which loops through the current sensing device on the main PCB. This wire is terminated at the red cylinder plug at the cylinder.

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