Honeywell 1EN2R-9005, 0406R3-NE User Manual

L41../L61.. SERIES

THERMOSTAT (AQUASTAT)

PRODUCTION HANDBOOK

APPLICATION

The L41../L61.. series aquastats are primarily designed for
application on water filled heating systems and systems for hot
water supply, mainly domestic use.

Subject to change without notice. All rights reserved.

Contents

General page

Description of device functions .........................................2

Description ........................................................................ 3

Overview/selection guide ................................................. 4

Features ............................................................................5

Aquastat series

L4188 - L6188 .................................................................. 6

L4189 - L6189 .................................................................. 8

L6190 ............................................................................. 10

L4191 - L6191 ................................................................ 12

L6188A 2044 Tradeline .................................................. 14

Performance .................................................................... 16

Construction .................................................................... 17

Various

Accessories and spare parts ........................................... 18

Quality assurance statement ........................................... 20

Standards and approvals ................................................ 20

Ordering information ........................................................21

1 EN2R-9005 0406R3-NE

DESCRIPTION OF DEVICE FUNCTIONS

Aquastats thermostats

Honeywell manufactures a coprehensive range of water
temperature thermostats (trade name Aquastat) for controlling
and limiting boiler water temperature in hydronic heating
systems.
These sensitive, fast response devices are available in either
direct, panel or surface mount versions.

Sensing element

The liquid filled sensing element, including well or sensor
assembly, responds to temperature changes of water in a
heating system.
The sensor element has a diaphragm type power head
connected to a tube type capsule, through a small bore
capillary.
Expansion of the liquid, which completely fills the sensing
element, is the means of motion of the diaphragm.
The sensor assembly, used on the surface mounted aquastat,
envelopes the sensing capsule by means of an aluminium
heat shield for better heat conduction, an insulator of
glasswool and a mounting bracket.

Control mechanism

The control mechanism is mounted into the thermoplastic
housing. The mechanism transfers the motion of the
diaphragm to a snap action switch (Micro Switch) and also
provides the facility to adjust the temperature level on which
the Micro Switch has to operate.
The mechasnism consists of a two piece lever with calibration
screw, a plastic actuator for the switch, a cam and shaft for the
set-point adjustment, a loading spring for cam and levers and
a pad with pushplate to transfer the diaphragm motion to the
lever.

Knob with scale and index

The plastic knob with scale and index enables the user to
adjust the Aquastat on a selected temperature setting within
its range. The knob fits on the cam and stays on it due to the
force of the spring on the nave of the knob.
This spring force enables the installer to pull the knob from the
cam without the use of tools.
The hole in the knob and the shaft of the cam are provided
with a flat side which allows mounting of the knob only in one
position in order to maintain the calibration.
The plastic index will be fastened by means of two M4 thread
forming screws on the housing.

Micro Switch

The Micro Switch mechanism is also mounted into the plastic
housing. the mechanism consists of a snap action spring type
PL with contacts and a moveable or a fixed and a stationary
contact bracket.

The Micro Switch mechanism is intended to control electrically
a burner, a relay, etc. in dependency of the temperature
changes in a heating system.
On choice the Micro Switch mechanism can be delivered with
the following contact arrangements:

• Single Pole Single Throw,
C-1 breaks on temperature rise

• Single Pole Double Throw,
C-1 breaks on temperature rise.
C-2 makes on temperature rise.

The contacts are connected to 6.3 mm terminals which are
extending from the outside of the Aquastat housing.

Cover and conduit entries

The housing(s) of the Aquastat can be provided with conduit
boxes which are provided with holes to fit Pg 13.5 conduits.
To obtain easy wiring possibilities these boxes can be
mounted or disconnect without the use of tools (hook in
approach).
The conduit box is locked with the front cover, which is
fastened by means of an M3 thread forming screw. Also the
top cover is locked by the front cover.

Set-point stops

On request, the Aquastat can be delivered with a high and low
limit stop. The purpose of these stops is to provide the user
with the facility to choose a maximum and/or minimum setting
on the scale.
The stop is situated on the rear side of the setting knob.
Adjustment is only possible after removal of the knob.

Manual or tool reset

On request, the Aquastat can be delivered with a manual reset
or a tool reset feature.
The tool reset feature is covered by the front cover.
Operating of the reset button is only possible after removal of
the front cover.
The manual reset button potrudes the front cover of the
Aquastat and resetting can be done without the use of a tool.

Adjustable differential

On request, it is possible to deliver the Aquastat with an
adjustable switch differential.
The adjustable switch differential feature consists of a plastic
adjusting dial with pointer, which is connected to a moveable
contact.
Turning of the dial changes the contact gap of the Micro
Switch and thus the differential.
The dial is situated under the front cover or behind the panel.
Adjustable differential feature is only applicable on controllers
and recycling limit controls

EN2R-9005 0406R3-NE 2

DESCRIPTION

The L41../L61.. series aquastats are sensitive water tempera­ture control, which are provided with a liquid filled sensing sys­tem.

The following main types are available:

• Single, panel mount immersion

Aquastat with remote bulb to select the most favourable
position on a boiler or vessel.

• Single, direct mounted immersion

Aquastat with insulating cover to protect against accidential
touching of live parts.

• Dual, direct mounted immersion

Dual Aquastat and consisting of two basic single units,
which are mounted together and protected by one common
cover and using one well for the two sensors.

• Single, surface mounted

The sensor of this type is to be mounted directly on the
surface of a boiler or pipe in a heating system. The
Aquastat mechanism is directly attached to this sensor.

The L41../L61.. series aquastats are primarily designed for
application on water filled heating systems and systems for hot
water supply, mainly domestic use.

The L41../L61.. series aquastats can be divided in the
following main types:

• Controller

Controls the water temperature in accordance with the
setting of an external knob (TÜV-type TR)

• Recycling limit control

Limits the water temperature below or above an adjusted
level and resets automatically. This type has a greater
differential and no external knob (TÜV-type TW).

• Thermal cut-out with external reset button
(manual reset)

Limits the water temperature on a maximum adjusted level.
This type does not reset automatically and it does not have
an external knob.

• Thermal cut-out with internal reset button (tool reset)

Limits the water temperature on a maximum adjusted level.
This type does not reset automatically and it does not have
an external knob.

3 EN2R-9005 0406R3-NE

OVERVIEW/SELECTION GUIDE

Application Single Aquastat thermostats Dual Aquastat thermostats

Controller or limiter thermostat Controller and limiter thermostat with standard

Direct mount (immersion)

sensing element

Panel mount (immersion)

Surface mount
(with mounting strap)

Replacement aquastat (immersion)

L4188A, B, C
25 ... 95°C
40 ... 110°C
70 ... 140°C

L4189A, B, C 25 ...
95°C 40 ... 110°C
110 ... 230°F

L6190A, B, C
25 ... 95°C

L6188A, B, C
25 ... 95°C
40 ... 110°C
70 ... 140°C

L6189A, B, C
25 ... 95°C
40 ... 110°C
70 ... 140°C
110 ... 230°F

L4191A, B and L6191A, B
25 ... 95°C
50 ... 95°C
40 ... 110°C
70 ... 140°C

L6188A 2044
40 ... 110°C

EN2R-9005 0406R3-NE 4

FEATURES

• 6.3 mm quick connect terminals for receptacles

• Mounting either in a horizontal or vertical position.

• Housing is provided with two mounting holes which are

suitable for M4 thread forming screws, for mounting on a
control panel.

• Cable entry in the conduit box is suitable for Pg 13.5
conduit or is provided with a plastic grommet (at choice).

• The high and low setpoint stops are field adjustabe with
steps of 2.5°C.

• Capillary available in 350 mm (optional), 1000 mm
(standard), 1500 mm (optional) and 2000 mm (optional)
length.

• Surface mounted Aquastat can be mounted on
cylinders of 300 ... 460 mm diameter as well on pipes
from 40 ... 150 mm diameter.

• Wide range of well assemblies available.

5 EN2R-9005 0406R3-NE

L4188 - L6188 SINGLE AQUASTAT - DIRECT IMMERSION

APPLICATIONS AND ORDERING INFORMATION

Application

L4188 and L6188 are sensitive, immersion-type water
temperature thermostats for controlling and limiting boiler
water temperature in hydronic heating systems.

The thermostat has a liquid-filled sensing element which fits
into an immersion well (order separately) for direct mounting
into a boiler, tank or other vessel.

Ordering information

O.S. number Application Temperature

range

L4188A 2015 Controller 25 ... 95°C 4 SPST External knob ­L4188A 2023 Controller 40 ... 110°C 4 SPST External knob 5
L4188A 2031 Controller 25 ... 95°C 4 SPST External knob 5
L4188B 2005 Controller 40 ... 110°C 4 SPST Internal screw 4 - 5
L4188B 2013 Controller 25 ... 95°C 4 SPST Internal screw 4 - 5

L6188A 2002 Controller 25 ... 95°C

L6188A 2010 Controller 40 ... 110°C

L6188A 2028 Controller 25 ... 95°C

L6188A 2036 Controller 70 ... 140°C

L6188A 2044 Controller 40 ... 110°C

L6188B 2000 Controller 25 ... 95°C 4 SPDT Internal screw 4

L6188B 2018 Controller 70 ... 140°C

L6188B 2026 Controller 40 ... 110°C

L6188B 2034 Controller 25 ... 95°C

L6188B 2042 Controller 25 ... 95°C 4 SPDT Internal screw
L6188C 2008 Limiter 70 ... 140°C Manual reset SPDT Internal screw 7
L6188C 2016 Limiter 25 ... 95°C Manual reset SPDT Internal screw 6 - 7

Switch
differential (K)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

4 ... 10
(adjustable)

Switch type Setting means Remarks

(see notes)

SPDT External knob 6

SPDT External knob 6

SPDT External knob 3

SPDT External knob 6

SPDT External knob Tradeline 1 - 7

SPDT Internal screw 3 - 7

SPDT Internal screw

SPDT Internal screw 6 - 7

1 = High limit stop
2 = High limit stop at 60°C
3 = Capilliary length 1500 mm and mounting bracket
4 = Without cover and conduit box
5 = Quick connect terminals only
6 = With well assembly
7 = With push-in plug

EN2R-9005 0406R3-NE 6

L4188 - L6188 SINGLE AQUASTAT - DIRECT IMMERSION

Specifications

Ambient temperature limits

0 ... 70°C

Electrical connection

6.3 mm spade terminals

Enclosure

IP40

Electrical rating

10 A at 250 Vac, resistive load

2.5 A at 250 Vac, inductive load

15 A at 250 Vac, locked motor
250 mA at 30 mVdc (special option)

Ter minal data

C-1 breaks on temperature rise (SPDT and SPST)
C-2 makes on temperature rise (SPDT only)

Accessories

11.5

11.5

48

32

47.1

Immersion wells, see page 18

Fig. 1. Internal schematics L4188/L6188

14.6

C+1 C

SPDTSPST

12

+

5

85

72

9

14.4

14

48

C12

4

21

Pg 13.5

48

30

Fig. 2. Dimensional drawing L4188/L6188

7 EN2R-9005 0406R3-NE