Alto-Shaam 2DN, 3DN Serv Ic E, Manua L Con Trol, THE RMOS TAT and HEAT LIGH T SEQUE NCE, Circuit

SERV IC E

MANUA L CON TROL

THE RMOS TAT and HEAT LIGH T SEQUE NCE

Whenev er the the rmostat

is turned “ON,”

the heat

indicator

light

will

indicate

the

power ON/ OFF conditi on of

the

heatin g cable,

and cons equ ently, the

cycling

of

the

cabinet

as

it

maintains

the

dialed cavity

tempe rature.

If

the

light does not

illu minate after normal

star t-u p,

the

main

power

sour ce,

thermostat, and/or

light must be

chec ked .

If

the warming

cab inet

does not

hold

the

temperatur

e as

dialed,

the

calibr ati on

of the thermostat

mus t

be

chec ked.

If the

warmer fails

to heat or

heats

con tinu ously

with

the

thermostat

“OFF,”

the thermo stat must

be

ini tially

checked for proper

operation.

If these

items are

checked and found to

be in ord er, a continuity

and

resistan ce check of the heat ing

cable shou ld be mad e.

SEE

CIRCUIT

DIAGRAM .

THE RMOS TAT CALIBRAT ION

The thermo stat

is precis ion calibrated

at

the factory.

Norm ally, no

adjustment

or recalibration

is

necess ary

unl ess

the thermostat

has been mis handled in transit,

changed

or abu sed while

in service.

A thermostat

with

a

sensing

bulb

operat es

on hyd rau lic

pres sure , conseq uently,

any

bending

of the

bulb

results in

a change

in

its

volum e, and alter s the accuracy

of

the

thermostat

cali bration.

A thermo sta t should be checked

or

recalibrated

by

placing

a quality,

thermal ind icator at

the

center of

an empty

hol ding cavity.

DO NOT CALI BRATE WITH ANY FOOD PRO DUCT IN THE CAB INET . The

thermostat

should

be set at

140° F (60° C),

and

should be allowe d to stabiliz e at that setting

for

a minimum

of

one

hour.

Fol lowin g temper atur e stabi lizat ion,

the

center

of the thermal swing

of

the air

tempera ture within

the

cabinet

should

appr oxima tely

coincid e with

the

thermostat

dial setting.

If calibrat ion is

neces sary, the calibration

screw

should

be adjusted

with

great

car e.

The

calibra tion scr ew of

the

thermo stat is loca ted

in the thermostat

dia l shaft.

With the shaft held stationary,

a minute, clockwise

motion

of

the cali bra tio n scr ew

appr eciab ly

lowers

the thermostat

setting.

A reverse , or

counter-clockwis

e motion

apprec iably

raises the thermos tat

setting.

After

achieving

the

desire d cycling

of

the

therm ostat , the calibra tion

scre w must

be sea led.

Place a few drops

of enamel sealant

dir ectl y on the calibration screw.

(RED NAIL POL ISH OR EQUIVALENT

IS ACCEP TABLE.)

Repair s sho uld			be made by auth oriz ed	ser vic e age nt s only.
TROUBLE	S HOOTING		CHE CKLI ST • ELEC TRON IC				CONTROL
TROUBLE			POSS IBLE CAUSE			REMEDY
Unit does not operate.		Insuf ficient power supply.		Chec k power source.
		Defective power cord or plug.		Check	and replac e if necessar y.
No displa y in electronic	control.	Faulty power supply board.		Check	line voltage		for 24V across
				pins 7 and 8 on the power supply board and
				across terminals J9 and J10 on the electronic
				control.
		Faulty electr onic control .		Replac e control.
Cann ot contr ol temperature but		Faulty relay		Replace		relay.
sensor and electroni c contro l
checks O.K .		Heating element ground ed.		Replace		element.
Tempera ture readout incor rect.		Dirty or faulty sensor.		Check sensor at 32°F (0°C).
				If Ohm reading is 100,
		Faulty control.		replace		display.
				If Ohm reading is not 100,
				replace sensor.

Dr awe r Warm er Ins tallation/ Operation/Service Manu al • 15.