Aprilaire 1180, 1150, 1160 installation instructions Automatic Mode Operation Notes

6. If all is set up properly, the ‘Steam’ indicator light on the humidifier will

illuminate and the heaters will be energized. In the ‘Test’ position, the

humidity demand will last for one minute.

AUTOMATIC MODE OPERATION NOTES

7.	If the ‘Steam’ indicator light does not illuminate when the Control is
	turned to the ‘Test’ position, refer to the troubleshooting section of
	this manual.
8.	Setting the Control:
	• If using Automatic Mode and the conditioned space is occupied,
	set the Control to knob-setting 4.
	• For Manual Mode and the conditioned space is occupied, set to 35%
	or to a level that matches the application’s needs.
	• If the conditioned space is unoccupied, set the Control to ‘Off’

For information on the initial adjustment period, refer to the operation notes in the next section.

The Automatic Steam Humidifier Control is installed in the return duct. During the first heating season, the Automatic Steam Humidifier Control needs to be adjusted to match the requirements and construction of the conditioned space. Please follow these steps when adjusting the Control (refer to Figure 12)

FIGURE 12

	7
	6
		T
	R	E
			S
5	E		T
			T
		S		/
		E
4
3			F
		F
		O

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AUTOMATIC MODE

90-902

9.Make sure the Red Diagnostic Light on the Control (see Figure 10) is not lit. If the Red Diagnostic Light is lit, re-check the wiring. If the Red Diagnostic Light does not go off, refer to the troubleshooting section of this manual. Note that the Red Diagnostic Light will turn on momentarily when first powered up.

FIGURE 10

9 12 R17

		1 2 3	Red Diagnostic
6	15		Light
		JP2
I+	I- 24V	C H+ H-	ODT

90-891

CAUTION

A high relative humidity setting on the Control may cause excessive condensation on windows and within walls. Set the

relative humidity in accordance with the instructions in this manual. Do not set the relative humidity higher than recommended.

OPERATION NOTES FOR MODULATING CONTROL FOR MODEL 1160 & 1180

As explained in the ‘Principles of Operation’ section of this manual, when configured for modulating control, the Automatic Steam Humidifier Control sends a 0-10V signal to the humidifier to vary the capacity of the Steam Humidifier depending on where the measured return air relative humidity falls relative to the set-point as well as the proportional control band. This will result in a more precise control of relative humidity.

The proportional control band can be set to 6%, 9%, 12%, or 15% RH. The

factory-setting is 12%. Note that the proportional control band is centered
on the RH set-point. Refer back to Figure 1.
If the humidifier is cycling on and off too
		FIGURE 11
frequently, the proportional control band
setting may need to be widened. To change,	9		12
use a small flat-head screwdriver to rotate
the potentiometer in the Automatic Steam
Humidifier Control board. See Figure 11.	6		15

90-901

Turn the dial to a setting of “4”. At this setting, when the Outdoor Temperature is 20°F, the indoor relative humidity set-point of the Automatic Steam Humidifier Control will be 35% RH. During the next 24-48 hours, it may be necessary to adjust the dial for more or less humidity, depending on the occupants’ comfort and the requirements of the conditioned space. Refer to the ‘Operation Guide’ (Table 1).

During the coldest portion of the first heating season, minor adjustments may be necessary. This is dependent upon the unique features and construction of the conditioned space. Refer to the ‘Operation Guide’ (Table 1).

TABLE 1: Operation Guide

ConditionSolution

Condensation on windows. Reduce the setting on the control

	dial by 1 increment.
Lack of humidity.	Increase the setting on the control
	dial by 1 increment.

The relative humidity in the conditioned space will now be accurately controlled and should need no further adjustment during future heating seasons. Make note of the dial setting in the event the knob is temporarily moved when performing annual maintenance of the Aprilaire Steam Humidifier.

Table 2 below shows the way the Automatic Steam Humidifier Control automatically adjusts the relative humidity based on the outdoor temperature. For example, when the knob is set to “4” and the outdoor temperature is 20°F, the conditioned space will be controlled to 35% RH.

			TABLE 2: Relative Humidity Guide
				Outdoor Temperature (°F)
		-20	-10	0	10	20	30	40	50
	1	–	–	–	10	15	20	25	30
Setting	2	–	–	12	17	22	27	32	37
	4	15	20	25	30	35	40	45	50
	3	–	13	18	23	28	33	38	43
Dial	5	22	27	32	37	42	47	52	55
	6	28	33	38	43	48	53	55	55
	7	35	40	45	50	55	55	55	55

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