Aerovent IM-500 User Manual

Page 10

Aerovent IM-500

Adjustable Pilot

(Aerovent Part #1192-01E)

The pilot is properly adjusted at the factory; however, the

conditions of the installation can affect this pre-adjusted

pilot so that it may require resetting. The pilot has a needle

valve adjustment under the brass screw cap. Remove the

brass screw cap to make the pilot flame adjustment. The

pilot works best with the smallest possible flame, and this

is usually with the needle valve screw backed out

to 1

turns from the fully closed position.

There are three (3) fully modulating temperature

control systems offered:

OUTLET TEMPERATURE CONTROL SYSTEM

(OTC, Series 14) holds constant outlet temperature

adjustable at the remote operating station and has out-

door temperature compensation.

The discharge air temperature thermostat actuates

the modulating regulator to hold average outlet tempera-

ture to a set point located in the remote station.

OUTLET TEMPERATURE CONTROL SYSTEM

(OTC-RO, Series 14 w/T115 Override) with room over-

ride (Optional) A T115 room space temperature control

increases the discharge air temperature until room tem-

perature is satisfied. The room set point is adjustable.

This system does not allow a room to fall below the

set point of the Room Override thermostat. Once the

room thermostat is satisfied, the temperature is then

backed down to the TD114 set point. The increase of

temperature is controlled set by a selector dial on the

back of the TD114.

Discharge air temperature thermostat automatically

limits extreme changes in discharge temperature.

MODULATED ROOM TEMPERATURE CONTROL

(MRTC, Series 44) (Optional) maintains room tempera-

ture within very narrow limits, provides extreme accu-

racy and rapid response to small temperature changes.

Compensates for process heat while maintaining the

room temperature.

Go to the Maxitrol web site at www.maxitrol.com for

the Maxitrol bulletin that pertains to the system supplied

with your unit. The front specification page lists the type

of temperature control system.

Maxitrol Temperature Control Modulating Gas

Valves (MR212 valve)

Units are supplied with a Maxitrol Series 14 or 44 tempera-

ture control modulating system. The Maxitrol temperature

control responds to a DC voltage signal from the Maxitrol

Series 14 or 44 amplifier. When the DC voltage is in the

range of 0 to 5 volts the main valve is at low fire; modulates

between 5 and 15 VDC; at 15 volts the valve is full open

and is at high fire operation. As the DC voltage changes,

a solenoid valve in the main valve modulates. Low fire is

accomplished by means of a mechanical bypass built into

the valve body. This adjustment is located under the valve

cover and should be adjusted on all installation start-ups.

Maxitrol Modulating Valve Adjustment

NOTE: Low fire adjustment should be checked whenever

the high fire adjustment is changed.

High Fire Manifold Adjustments

1. Disconnect wires from terminals #2 and #4 on the

A1044 or #4 on A1014 Amplifier. This causes the valve

to call for continuous high fire.

2. Remove seal cap (A), Figure 12, and turn regulator pres-

sure adjusting screw to obtain desired manifold pressure.

(7 in. w.c. MAXIMUM) (Clockwise rotation increases

pressure.) The manifold pressure must not exceed 7

in. w.c. The flame must always be checked visually. The

Figure 10. Adjustable Orifice

Figure 11. MR212 Valve

Figure 12.