Maxitrol A1044 Installation Manual

SERIES 44 INSTALLATION INSTRUCTIONS

and field service checklist

Table of Contents

Page 2 Introduction and Dimensions
Page 3 Specifications

Installation of Components

Typical Gas Trains
Page 4 & 5 Field Service Checklist
Page 6 Wiring Diagrams

Valve Adjustments
Page 7 Preliminary Circuit Analysis
Page 8 Temperature Calibration

Low Fire Start Time Adjustment

Sensitivity Adjustment

A1044L1 Amplifier

Selectrastat

Valve

Temp. Sensor

A1044 Amplifier

Temp. Selector

Mixing Tube and Sensor

BULLETIN MI2047-06/04

REPLACED MI1079

System Components

Amplifiers:

A1044 (min. 40° to 80° F/ max. 80° to 140° F)
A1044C (min. 20° to 60° F/ max. 80° to 140° F)
A1044D (min. 20° to 60° F/ max. 35° to 75° F)
A1044E (min. 20° to 60° F/ max. 60° to 120° F)
A1044L1, A1044CL1, A1044DL1, A1044EL1, A1044FL1 ­above ranges with adjustable low fire start duration

NOTE: Amplifier and Discharge Temperature Sensor must

have same temperature range to be compatible.

Discharge Temperature Sensors: use with Mixing Tube
TS144 (min. 40° to 80° F/max. 80° to 140° F)
TS144C (min. 20° to 60° F/max. 80° to 140° F)
TS144D (min. 20° to 60° F/max. 35° to 75° F)
TS144E (min. 20° to 60° F/max. 60° to 120° F)
TS144F (min. 40° to 60° F/max. 60° to 95° F)

Mixing Tubes: used with Sensors
MT1-9 or MT2-9 (9" length)
MT1-12 or MT2-12 (12" length)
MT1-23 or MT2-23 (23" length)
MT1-28 or MT2-28 (28" length)
MT1-57 (57" length)

Valves:

M411 (3/8" & 1/2" pipe size)
M511 (1/2" & 3/4" pipe size)
M611 (3/4" & 1" pipe size)
MR212D (1", 1¼", 1½ pipe size)
MR212E (1½" & 2" pipe size)
MR212G (2½" & 3" pipe size)
MR212J (4" flanged)
MR212D-2, E-2, G-2 & J-2 (same pipe sizes as MR212D-J
except used for 2-speed blower or dual fuel operation)

NOTE: M (Modulator) valve requires an upstream pressure

regulator for low fire & high fire settings.
MR (Modulator/Regulator) valve requires no
upstream pressure regulator up to 5 psi inlet.

Selectrastat (Senses & Selects):

T244 (55° to 90° F)
T244A (40° to 80° F)

or optional pair to replace Selectrastat:

Space Temperature Selector:

TD244 (wall mount 55° to 90° F)
TD244A (wall mount 40° to 80° F)
TD244P (panel mount 55° to 90° F)
TD244AP (panel mount 40° to 80° F)

Space Temperature Sensor:

TS244 (55° to 90° F)
TS244A (40° to 80° F)

NOTE: Space Temperature Selector and Space

Temperature Sensor must have same
temperature range to be compatible.

Introduction and Dimensions

Selectra SERIES 44 electronic gas flame modulation
systems are designed primarily for space heating, as
components of direct fired equipment. They may be
field installed on existing equipment or specified for new
equipment installation. All fuel gases are compatible.

The systems utilize Modulator or Modulator-Regulator
valves to control gas pressure. Amplifiers are available
with adjustable low-fire start duration.

SELECTRASTAT, TEMP. SELECTOR, SPACE TEMP. SENSOR

A discharge air temperature sensor (and mixing tube) is a
means of limiting the minimum and maximum discharge air
temperature. The amplifier supplies output voltage to the
modulating valve. A wall mounted Selectrastat senses
space temperature and has an integral selector with either
a 55° to 90° F or 40° to 80° F range. Optionally, a remote
Temperature Sensor paired with a separate Temperature
Selector can be substituted for the Selectrastat.

(Space Temperature Selector dimensions same)

A1044 AMPLIFIER

A1044L1 AMPLIFIER

(Space Temperature Sensor dimensions same except without front dial)

MIXING TUBE (TS144 attaches internally)

(SEE PAGE 1)

2

Specifications

Pressure Adjustment Ranges: (Maximum Fire)

Standard (MR212) ................. 2" to 5" w.c. / 5 to 12 mbar

Standard (MR212-2) .............. 2" to 5" w.c. / 5 to 12 mbar

reduced 0" to 3" w.c. / 0 to 7.5 mbar
Vent: Model M411, M511, M611-vertical vent outlet 1/8"
NPT—12A06 installed.
MR212—two vents located in upper housing, both
equipped with vent limiting means.

Ambient Limits:

Operating -40° to 125° F / -40° to 52° C
Non-Operating -50° to 185° F / -46° to 85° C
Power Requirements: 24 Volts, NEC Class ll
transformer 20 VA

NOTE: Transformer secondary must not be grounded
in any portion of the circuit external to a Maxitrol
amplifier. If existing transformer is grounded, a
separate isolated transformer must be used. Electrical

Installation of Components

Wiring Run: Control wires connected to the Selectrastat,
Discharge Air Sensor, Remote Temperature Selector/
Sensor, Amplifier or Valve must not be run close to or
inside conduit with power or ignition wires. Doing so

may cause the unit to function erratically or may
destroy the amplifier. If shielded wires are used, shield

must be insulated and grounded at the amplifier location
only.

Amplifier: Install in any convenient location that is
protected from the weather and contaminated
atmosphere.

interference may effect performance and/or damage
equipment.
Gases: All fuel gases
Pressure Limits:

Maximum M411, M511, M611 Outlet Pressure: 7.0" w.c.
/17 mbar
MR212 Outlet Pressure Springs: 1" to 3.5" w.c. / 2.5 to 9
mbar, 2" to 5" w.c. / 5 to 12 mbar, and 3" to 8" w.c. / 7
to 20 mbar

Static Pressure Rating (M411, M511, M611 ) ..... 5.0 psi

/345 mbar

Maximum Operating Inlet Pressure (MR212) ...... 5.0 psi

/345 mbar

Maximum Emergency Exposure *(MR212)...... 12.5 psi

/862 mbar
*May not function properly at this pressure, but will suffer

no internal damage.

Selectrastat: This component selects and senses space
temperature. Remove cover to mount in heated area
where representative space temperature can be sensed.

Optional:

Remote Temperature Selector: Not temperature
sensitive (selects space temperature). Remove cover to
mount in any convenient location. Note: Temperature

selector and sensor must have same temperature range to
be compatible.

Remote Temperature Sensor: Senses space
temperature. Remove cover to mount in area where
representative space temperature is to be sensed.

Typical Gas Trains

Modulator (M) or Modulator-Regulator (MR) Valve: Mount in upright position in horizontal run of pipe, downstream of
other controls - a separate gas pressure regulator must be used with any modulator (M) valve.

MR Valve: Modulator-regulator valve

M Valve: Regulator upstream of modulator valve

3