Nortec 132-3091 User Level, Informing The User, Self-Help, System Messages, Remote Indication

USER LEVEL

The keypad has four keys: MENU, ￿ , ￿,

ENTER.

Each time the user presses the menu key, the microcomputer will display on the LCD the next operating parameter on the menu. The basic display will read:

-Steam output (lbs/hr)

-Capacity demand

-Limited capacity

-Control signal y

The display loops back to the top of the menu the next time the user presses the menu key. As NORTEC software updates are incorporated, new parameters will automatically be added to the menu.

INFORMING THE USER

The microcomputer continually monitors the operating status and informs the user in four ways. The first (signal light status), second (optional external lamps tied to the control strip) and third (operating parameters displayed on the alphanumeric LCD display) have been discussed. The fourth way is to interrupt the LCD and display a system message. It only does this as a last resort.

SELF-HELP

The microcomputer applies corrective actions

whenever its self-diagnostics identifies a problem that it is able to correct by itself. If the corrective action is not successful then it displays a system message. If the corrective action requires a service person, then the microcomputer’s only resort is to stop the unit and display a system message. The unit never stops unless it has to.

After three days of no call from either the on/off controls or the modulating controls, the drain valve is automatically activated long enough to drain all water from the steam cylinder. This NORTEC exclusive feature will prolong the life of the cylinder.

SYSTEM MESSAGES

Alphanumeric system messages will appear on the LCD display any time the microcomputer decides the user must be informed. The microcomputer does not stop the unit for all system messages. (See the Troubleshooting Section in this manual)

REMOTE INDICATION

The NHMC is always internally wired to provide 24 VAC to the terminal strip for optional external remote indication. Up to 100 milliamps is available at each of three terminal pairs (61-20, 62-40, 63-36) for activating yellow, green and red lamps ordered as options from NORTEC or for powering field-supplied resistive loads such as lamps.

DOUBLE UNIT OPERATION

Turn both switches on. During start-up self test both sides respond to the self test together. Watch for the lamps to light and the drain, fill and contactor to energize as described on page 15. The LCD, however, only indicates the left circuit [1].

After the self test, the LCD will display the steam output for the left side [1] and both sides will operate normally.

To alternate between parameters for the left side

[1]and parameters for the right side [2], press the Enter key.

Use the MENU key to see other parameters besides steam output. To display steam total output for both sides press the enter key until [￿] is displayed.

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

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.

Display is not available for the right side [2] if the left side is switched off.

NHB/NHP OPERATION

END OF CYLINDER LIFE

When the cylinder is used up and water level can no longer stabilize below full cylinder (due to fully coated electrodes), the yellow light will come back on, in addition to the green light. The disposable cylinder must be replaced.

Although “both lights on” is the same signal at start-up as it is at end of cylinder life, the age of the cylinder enables the user to know when “both lights on” is indicating end of cylinder life. It is wise to keep a new replacement cylinder on hand to avoid downtime when it becomes time to change the disposable cylinder. (See Troubleshooting section.)

- 9 -