Honeywell L4188 User manual

INSTRUCTION SHEET
1 MU1R-9023 0208R12-NE
L4188/L6188A, B, C AND L4191/L6191A, B
AQUASTAT CONTROL
APPLICATION
The L4188/L6188 and L4191/L6191 aquastat thermostats
are sensitive direct immersion type water temperature
thermostats for limiting and controlling boiler water
temperature in hydronic heating systems.
The L4188/L6188 aquastat thermostats are single aquastats.
The L4191/L6191 aquastat thermostats are dual aquastats
i.e. two independent controls (controller and limiter housed
under a single cover).
The L4188/L6188 and L4191/L6191 aquastat thermostats
confirm with the following EC directives:
Low Voltage Directive 73/23/EEC
Electro Magnetic Compatability Directive 89/336/EEC
Compliance with the EMC directive regarding emission can
only be determined in the application.
SPECIFICATIONS
Model
See table 1 page 2
Ambient temperature
0 ... 70 °C
Capillary length
0.22 m, 1 m, or 1.5 m
Electrical connection
6.3 mm quick connect terminals suitable for 1/4” receptacles.
The L6188 and L6191 series thermostats are provided with
adapters for screw connection
Electrical rating
10 A at 250 Vac, resistive load
2.5 A at 250 Vac, inductive load
15 A at 250 Vac, locked rotor
2 A at 24 Vac, inductive load
250 mA at 30 mVdc (special option)
Terminal data (see fig.1 and 2 )
C-1 breaks on temperature rise (SPST and SPDT)
C-2 makes on temperature rise (SPDT only)
Immersion wells (must be ordered separately for bulk pack
aquastats)
** Insertion length including thread of brass spud
Maximum well pressure: 10 bar for single and multi wells
(ND 10)
Type Insertion
length (mm)
Thread** Order number
Single 105 1/2” BSPT 45.900.409-003
169 1/2” BSPT 45.900.409-006
Dual 105 1/2” BSPT 45.900.409-007

MU1R-9023 0208R12-NE 2
Table 1. L4188/L6188 and L4191/L6191 models
INSTALLATION
IMPORTANT
Take care that installer is a trained experienced
service man.
The L4188/L6188 and L4191/L6191 aquastats do
not require lubrication.
Mounting
Follow the mounting instructions supplied by the boiler or
burner manufacturer when available.
Where no special instruction is given, follow the procedure as
outlined below:
Drain the water from the heating system.
Screw the immersion well into a 1/4” or 1/2” pipe tapping
and tighten (use a good wrench, do not use the device
for this purpose).
Refill the heating system with water and test the
immersion well for water tightness.
Insert the temperature sensor(s) into the well untill it
bottoms and hold in position while securing with the
screw provided.
Wiring
CAUTION
Disconnect power supply to prevent electrical shock
and/or equipment damage.
Wiring must be in accordance with local regulations.
The appliance manufacturer’s instructions should
always be followed when provided.
Remove the front cover and conduit box(es) and insert
the cable through the conduit box(es).
Wire the thermostat into the circuit.
Mount the conduit box(es) and screw on the front
cover.
ADJUSTMENTS
WARNING
Adjustments must be made by qualified persons only.
If the appliance manufacturer supplies checkout and/
or service and maintenance instructions carefully
follow them. If these instructions are not provided
then use the procedure outlined below.
The L4188/L6188 and L4191/L6191 aquastats have
been factory calibrated, field calibration should not be
attempted.
Type Temperature range (°C) Switching differential (°C) Switch type Setting means
L4188A 25 ... 95
40 ... 110
4SPST Knob setting
L4188B Internal setting
L6188A 25 ... 95
40 ... 110
70 ... 140
4 ... 10 (adjustable)
SPDT
Knob setting
L6188B 4
4 ... 10 (adjustable)
Internal setting
L6188C 25 ... 95
70 ... 140
Manual reset SPDT Internal setting
L4191A
Controller
Limiter
25 ... 95
4
SPST
Knob setting
Internal setting
L4191B
Controller
Limiter
25 ... 95
70 ... 140
4 SPST Knob setting
Manual reset SPDT Internal setting
L6191A
Controller
Limiter
25 ... 95
50 ... 95
40 ... 110
4
4 ... 10 (adjustable) SPDT Knob setting
4 SPDT Internal setting
L6191B
Controller
Limiter
25 ... 95
40 ... 110
70 ... 140
4
4 ... 10 (adjustable)
SPDT
Knob setting
50 ... 95
40 ... 110
70 ... 140
Manual reset Internal setting
1
2
3
4
1
2
3

3 MU1R-9023 0208R12-NE
Differential setting
The adjustable differential can be set by turning the disc
located under the front cover.
The disc is turned using a screw driver.
The number in line with the point represents the differential
setting.
Limit resetting
Aquastat thermostats used as limit controls can be provided
with a manual or a tool reset button.
When the limit switch is opened, i.e. cut power off, wait untill
temperature drops below the reset value and
(i) For manual reset models:
Depress the button on the front cover
(ii) For tool reset models:
Remove front cover and depress the button on the
bottom left hand side of front plate.
Final checkout of the installation
Set appliance in operation after any adjustment and observe
a complete cycle to ensure that all burner components
function correctly.