Honeywell L404A-D specifications ffi

Boiler
Installation
If the
controller
is
being
used on a boiler installation
test
it
as follows
1 Note the boiler
pressure
by
checking
the boiler
pres
sure
gauge
To
perform
this
testproperly
the
boiler should
have a
pressure reading
near the middle
of
the controller s
main
scale
range
2
Turn the main scale
adjusting
screw
Fig
11 until the
m rlnscale
setting
indicator on
the
controller
corresponds
to
th
b9iler
pressure gauge
readiri
g
3
TheL404A or C should
break
the
control circuit
s
automatically
when the
boiler
pressure
gauge
reading equals
or
slightly
exceeds the
controller
setting
The L404B or D should make
the circliit
under the same
circumstances
The L404F
L604L M
should
inake
the
R
W circuit
and
break the R B
circuit under the same
circumstances
The L604A should
make the RI W
circuit and break the
R2B
circuit under the same
circumstances
4 If the controller
is
operating
properly
turn the main
scale
adjusting
screw
Fig
11
until the main
scale
setting
indicator isat the desired
set
point
If a
Controller Seems to
Operate
Improperly
If
the controller is
suspected
of
operating
iniproperly
it
may
be
further checked
as follows
Fig
12
1
Disconnect all
power
to
the
controller loosen the
cover screw and
remove the cover
2
DisconneCt the wires from
the controller
3 Connect
an ohmmeter between
the switch
terminals
4 Lower
the set
point
of the
controller
simulating
a
pressure increase
through
a
range
greater
than the differen
tial The switch
should either
make or
break
depending
on
the
model of the
controller
AnL404A orC should
break
an
L404B
or D should make
an
IA04F
L604L M
should
break
R B and make R
W and an
L604A should
breakR2 B and
make
RI W If it
makes the
ohmmeter reads
zero if it
breaks
the
ohmmeter reads
infinity
5 Raise the
set
point
of the
controller
simulating
a
pressure
decrease
through
a
range greater
than the differen
tial The
switch should break
or make
just
the
opposite
of its
action in
step
4
except
for the L404C
D and L604L
manual
reset models
NOTE
An
approximation
of the
differential
can be made
by
observing
the
change
in
set
point
required
for a resistance
change
from
zero to
infinity
6 If the
controller
operates
improperly replace
it
7
When the controller
is
operating properly
reconnect
the wires to the
terminal block
replace
the
cover and
tighten
the cover
screw and
reconnect the
power
L404A
D F L604A L M
SETTING AND
CHECKOUT
ffi
CAUTION
Do not
put
the
system
into service until
you
have
satisfactorily
completed
all
applicable
tests
de
scribed
in
this Checkout
section in the
Checkout
section
of
the
applicable
instructions for the flame
safeguard
control
and any others
required by
tlie
burner and boiler
manufacturers
Fig
12
Checking
controller
operation using
an ohmmeter
MAIN
SCALE
SETllNG
INDICATOR
00
INPUT
OUTPUT
o
280
ADJ
MAIN
SCALE
ADJUSTlNG
SCREW
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
ro
SETPOINT
DEqREASE
ZERO
OHMS
INANITY WHEN RB
BREAKS
AN l 604
WITH JUMPER INSTALLED
BElWEEN Rl AND R ISSHOWN
AN L404F
OPERATES SIMIlJ RL Y SPOT
SWITCHING AN L404A BC
OR 0 HAS
ONLY TWO
TERMINALS
SPSTSWITCHING AN L404A
OR C BREAKS AND
L404B OR 0 MAKES
WHEN THE SETPOINT
IS
DECREASED
FAfl ENOUGH
M8944