Forma Scientific 3911 User manual

Forma Scientific, Inc.
P.O. Box 649
Marietta, Ohio 45750
U.S.A. Telephone: [phone]
Telefax: [phone]
Model: 3911/3913
Reach-In Incubator
11 cu ft capacity
Manual No. 7013911
Rev-O
IMPORTANT!
Read This Instruction Manual
Failure to read, understand and follow the instructions in this manual may result in
damage to the unit, injury to operating personnel and poor equipment p&rformance.
Caution: All internaladjustments and maintenance must beperformed by
qualifiedservicepersonnel

Forma Scientific,
Do You Need Information or Assistance on Forma Scientific
Products?
If you do, please contact us 8:00 A.M. to 5:00 P.M. (Eastern Standard lime) at:
1-614-373-4763
Direct
1-800-848-3080 Toll Free, U.S. and Canada
1-614-373-4189
FAX
http://www.forma.com Internet Worldwide Web Home Page
Forma's Sales Group can provide information on pricing and give you quotations. We
cantake
your order and provide delivery information on majorequipment items or make
arrangements
to have your local sales representative contact you. Our products are listed on the
Internet and we can be contacted through ourInternet home page.
The
Forma Product Service Group can supply technical information about propersetup,
operation or troubleshooting
of your equipment. We can fIll your needs for spare or replacement
parts
or provide you with on-site service. We can also provide you with a quotation on our
ExtendedMaintenance Program for your Forma products.
Whatever Forma products you need or use,
we will be happy to discuss your
applications.
lfyou are experiencing technical problems, working together, we will help you
locate the problem and, chances are, correct it yourself...over the telephone without a service
call.
When more extensive service is necessary, we will assist you with the selection of a fIeld
service organization for on-the-spot repairs
by a professional field technician. Tfyour service
need is covered
by the Forma warranty, we will arrange for the unit to be repaired at our expense
and to your satisfaction.
Regardless
of your needs, Forma's professional telephone technicians are available to
assist
you Monday through Friday from 8:00 A.M. to 5:00 P.M. Eastero Standard Time. Please
contact us
by phoning or faxing us atthe above listed numbers. If you wish to write, our mailing
address is:
Forma Scientific, Inc.
POBox 649
Marietta,
OR 45750
International customers please contact your local Forma Scientific distributor.
111

Fonna Scientific, Inc.
--------------------------------------------~-----------
General Safety Notes used in this Manual
Important operating and/or maintenance instructions. Read the accompanying text
carefully.
Ce symbole attire I'attention de I'utilisateur sur des instructions importantes de
fonctionnement et/ou d'entretien.
II peut etre utilise seul ou avec d'autres symboles de
securite. Lire attentivement
Ie texte d'accompagnement.
Wichtige Betriebs- und/oder Wartungshinweise. Lesen Sie den nachfolgenden Text
sorgfsltig.
Importante instruccions de operacion y/o mantenimiento. Lea
el texto acompanante
cuidadosamente.
Potential electrical hazards. Only qualified persons should perform procedures
associated with this symbol.
Ce symbole attire I'attention de I'utilisateur sur des risques electriques potentiels.
Seules des personnes qualifiees doivent appliquer les instructions et les procedures
associees it
ce symbole.
Gefahrvon Stromschlagen. Nur qualifizierte Personen sollten die Tatigkeiten
ausfUhren, die mit diesem Symbol bezeichnet sind.
Potencial de riesgos electricos. Solo personas das capacitadadas deben ejecutar los
procedimientos asociadas con este simbulo.
Equipment being maintained or serviced must be turned off and locked off to prevent
possible injury.
Risques potentiels lies it I'energie. L'equipement en entretien ou en maintenance doit
etre eteint et mis sous clE~ pour eviterdes blessures possibles.
Gerste, an denen Wartungs- oder Servicearbeiten durchgefUhrt werden, mussen
abgeschaltet und abgeschlossen werden, urn Verletzungen
zu vermeiden.
EI equipo recibiendo servicio 0 mantenimiento debe ser apagado y segurado para
prevenir danos.
IV

Forma Scientific,
Hot surface(s) present which may cause bums to unprotected skin or to materials
which may be damaged by elevated temperatures
Presence de surface{s) chaude{s) pouvant causer des bralures sur la peau non
protegee, ou surdes matieres pouvant etre endommagees par des temperatures
elevees.
HeiBe Oberflilche{n) konnen ungeschlltzterHaut Verbrennungen zufOgen oder
Schaden an Materialien verursachen, die nicht hitzebesUindig sind.
Superficias calientes que pueden causar quemaduras a piel sin proteccion 0 a
materiales que pueden estar danados porelevadas temperaturas.
...J Always use the proper protective equipment (clothing, gloves, goggles etc.).
...J Always dissipate extreme cold or heat and wear proteetive clothing.
...J Always follow good hygiene practices.
...J Each individual is responsible for his or her own safety.
v

Forma Scientific, Inc. ______________________ ~ __
Table of Contents
SECTION 1 - RECEIVING
1.1 Preliminary Inspection................................................................................ 1-1
1.2 Visible Loss or Damage ............................................................................. 1-1
1.3 Responsibility for Shipping Damage........................................................... 1-1
SECTION 2 - INSTALLATION AND START-UP
2.1 Location .....................................................................................................2-1
2.2 Water (Humidity System) and Drain Connections........................................2-1
a. Connecting the Water Inlet for the Humidity System.............................2-1
b. Connecting the Drain Line .....................................................................2-2
2.3 RS-232 Output Interface and Remote Alarm Connector..............................2-3
2.4 Power Connection .....................................................................................2-4
2.5 Start-Up Procedure.....................................................................................2-4
2.6 Setting the Overtemp Safety Thermostat....................................................2-4
2.7 Setting the Undertemp Safety Thermostat...................................................2-5
2.8 Preparing the optional Cobex Recorder.....................................................2-6
a. Installing the Chart Recorder Battery ....................................................2-6
b. Changing the ChartPaper.....................................................................2-6
c. Changing the Pen.................................................................................. 2:-7
d. Calibrating the chart recorder................................................................2-7
2.9 Controller Configuration............................................................................2-8
Temperature Configuration
Humidity Configuration
SECTION 3 - CONTROL PANEL OPERATION
3.1 Main Power Switch and Indicator Light..................................................3-1
3.2 Refrigeration Switch and Indicator Light ................................................3-1
3.3 Defrost Switch and Indicator Light .........................................................3-1
3.4 Overtemp Safety Control, Indicator Light and Audible Alarm................3-2
3.5 Undertemp Safety Control, Indicator Light and Audible Alarm..............3-3
Vi

Forma Scientific, Inc. _______________________ _
3.6 Humidify Switch and Indicator Light.......................................................3-3
3.7 Dehumidify Switch and Indicator Light...................................................3-3
3.8 Audible Humidity Alarm and Indicator....................................................3-4
3.9 TemperaturelHumidity Controllers...........................................................3-4
3.10 Recorder (Optiona1)...............................................................................3-6
SECTION 4 - ROUTINE MAINTENANCE
4.1 Cleaning the Incubator..........................................................................
.. A-l
a. Maintaining the Humidity Steam Generator...................................... A-I
SECTION 5 - SERVICE
5.1 Access to Electrical Components............................................................. 5-1
5.2 Replacing the OvertemplUndertemp Probe and Thermostat................... 5-1
5.3 Replacing the Humidity/Temperature Sensor..........................................5-2
5A Replacing the Optional Recorder and Probe(s) .......................................5-3
5.5 Setting the
Door Heater Control ..............................................................5-4
5.6 Cleaning and Adjusting the Humidity Steam Generator...........................5-5
SECTION 6 - SPECIFICATIONS
SECTION 7 - SPARE PARTS LISTS
SECTION 8 - WARRANTY
SECTION 9 - DRAWINGS
SECTION 10 - SUPPLEMENTS
Vll

Forma Scientific, Inc.
SECTION 1 - RECEIVING
1.1 Preliminary Inspection
This item was thoroughly inspected and carefully packed prior to shipment and all
necessary precautions were taken to ensure safe arrival of the merchandise at its
destination. Immediately upon receipt, before the unit
is moved from the receiving area,
carefully examine the shipment for loss or damage. Unpack the shipment and inspect
both interior
and exterior for any in-transit damage.
1.2 Visible Loss or Damage
If any loss or damage is discovered, note any discrepancies on the delivery receipt
Failure to adequately describe such evidence
of loss or damage may result in the carrier
refusing to honor a damage claim. Immediately call the delivering carrier and request that
their representative perform an inspection. Do not discard any
of the packing material
and under
no circumstances move the shipment from the receiving area.
1.3 Responsibility for Shipping Damage
For products shipped F.O.B. Marietta, Ohio, the responsibility of Forma Scientific,
Inc. ends when the merchandise is loaded onto the carrier's vehicle.
On F.O.B. Destination shipments, Forma Scientific's and the carrier's responsibility
ends when your Receiving Department personnel sign a free and clear delivery receipt
Whenever possible, Forma Scientific, Inc. will assist in settling claims for loss or in-
transit damage.
1-1

Fonna Scientific, Inc.
SECTION 2 - INSTALLATION AND START-UP
2.1 Location
Locate the unit on a firm, level surface in an area of minimum ambient temperature
fluctuation. A minimum
of 12 inches clearance is required at the top of the incubator and
a
minimum of 3 inches clearance is required at the rear of the incubator to facilitate
adequate air flow around the refrigeration system.
2.2
Water (Humidity System) and Drain Connections
a. Connecting the
Water Inlet for the Humidity System
Do not attemptto operate the humidity system withoutfilling
it with water. The humidification heaterwill overheat, and
the overtemp safety thermostat will shut the humidification
system down.
The humidity reservoir will require approximately one quart (.946 liter) of water on
the initial filling. To ensure continuous satisfactory operation
of the incubator, only
distilled water should be used
in the humidity system. Purity of the water used in the
incubator humidifier reservoir must be within the 50K Ohm to 1 Meg
Ohm range to
protect, and prolong the life
of the stainless steel unit.
IMPORTANT:
Use
of tap water, or distilled water outside the specified range, will decrease the
operating life
of the unit and will void the warranty.
The water inlet is the 1/8" NPT connection located on the rear top left corner of the
incubator. Water inlet pressure at the unit should be from
15 to 40 PSI. A manual shut-
off valve should be installed between the main water supply and the incubator.

Forma Scientific, Inc.
2.3 RS-232 Output Interface and Remote Alarm Connector
The Model 391113913 is equipped with an RS-232 Serial Communication Interface for
the remote transmission
of temperature and humidity data. Remote alarm connections·are also
included on the terminal strip.
Key
o 0 o 0
00000000
1 2 3 4 5 6 7 8 9
Pin
# Description
1
2
3
4
5
6
7
8
9
temperature, Transmit Data
temperature, Receive Data
temperature, Common
humidity, Transmit
Data
humidity, Receive Data
humidity, Common
RS2I2 -Temperature
RS232 -Humidity
1
temperature, Common
temperature N.O.
tern erature N.C.
Remote Alarm Contacts
(Temferature and Humidity)
Terminal Pin Descriptions, RS-232 (1-6) and Remote Alarm Connections (7-9)
Figure 2-2
IMPORTANT USER INFORMATION
Cautionl Stored product should be
protected byan activated alarm system
capable
of initiating a timely response
24 hours/day. Forma Alarms provide
interconnect for centralized monitoring.
2-3

Forma Scientific, Inc.
Toprevent mineralbuildup on heater coils and humidity
generator walls, it
may be necessary to clean the humidity
generator
and immersion heaters with a non-metallic
abrasive
pad and flush thoroughly every two or three months.
Refer
to Section 4.2, aeaning theHumidity Generator and
Immersion Heaters.
b. Connecting the Drain Line
The cabinet's 3/8" MPT drain line connection is located on the rear (lower left side) of
the cabinet. A P-trap (Figure 2-1) is included with the unit and must be installed on the
connection. To install the drain connection:
L Using Teflon pipe thread tape, tape the threads on the cabinet drain connection.
2. Using an open end adjustable wrench, install the P-trap onto the connection. Make
sure that the trap
is positioned down.
3. Push a piece of 3/8" ID tubing onto the trap and direct the tubing to a convenient
drain. Install a hose clamp on the tubing,
if desired.
To cabinet drain
\ Figure 2-1
Cabinet drain p-trap
mv~
2-2

Forma Scientific, Inc.
2.4 Power Connection
The electrical junction box is located on the rear top section of the incubator. With
the junction box switch OFF, connect the incubator to an adequate power source. See
the electrical data plate mounted on the unit for exact electrical specifications.
2.5 Start-Up Procedure
When the humidification system is operational, the incubator may be started. Preset
the controls as follows:
Overtemp Safety Thermostat......................... (Fully Clockwise)
Undertemp Safety Thermostat....................... (Fully Counterclockwise)
Main Power Switch.......................................ON
Humidity Controller......................................Desired Setpoint
Temperature Controller.................................Desired Setpoint
Temperature Controller.................................Desired Setpoint
Door Heater .................................................40% (factory set)
For best overall performance the refrigeration switch should be turned on for most
applications. When running LowlNo humidity, at high temperatures, the refrigeration
switch may be turned off.
The defrost switch must be turned on when the temperature
setpoint is 10°C, or below.
2.6 Setting the Overtemp Safety Thermostat
Allow the chamber temperature and humidity to stabilize then set the overtemp
safety thermostat as follows:
1. Turn the overtemp control knob slowly counterclockwise until the audible alarm
sounds and the overtemp indicator lights.
2. Turn the overtemp control knob clockwise approximately two units on the scale. The
alarm should be silenced and the overtemp indicator light should go out.
2-4

Fonna Scientific, Inc.
The overtemp safety thennostat is now set a few degrees above the control
temperature setpoint. When the chamber temperature rises to the overtemp control point,
the alarm system will activate, power
to the heaters will shut off, and the chamber
temperature will be maintained at the overtemp control point.
When an overtemp condition occurs, the cause must be detennined and corrected
before normal operation under the main temperature controller can be resumed.
Note: When the chamber temperature control setpoint
is changed, the overtemp
safety thermostat must be reset
to accommodate the change.
2.7 Setting the Undertemp Safety Thermostat
Allow the chamber temperature and humidity to stabilize then set the undertemp
safety thennostat
as follows:
1. Turn the undertemp control knob slowly clockwise until the audible alarm sounds
and the undertemp indicator lights.
2. Turn the undertemp control knob counterclockwise approximately two units on the
scale. The alann should be silenced and the undertemp indicator light should go out.
The undertemp safety thermostat is now set a few degrees below the control
temperature setpoint. When the chamber temperature drops to the undertemp control
point, the alarm system will activate, power to the compressor will shut off, and the
chamber temperature will be maintained at the undertemp control point.
When an undertemp condition occurs, the calIse must be determined and corrected
before nonnal operation under the main temperature controller can be resumed.
Note: When the chamber temperature control setpoint
is changed, the undertemp
safety thermostat must be reset
to accommodate the change.
2-5

Fonna Scientific, Inc.
2.8 Preparing the (optional) Cobex Recorder
a. Installing the
chart recorder battery
The seven-day circular chart
recorder is located on the front
of
the incubator cabinet and is
protected by a glass door.
To prepare the recorder for
operation, open the glass door
and snap the connector onto the
9-volt battery as shown in Figure
2-2.
If the unit is operating, the
green LED lights steady.
If the
unit is not turned on, the LED
blinks.
slotted screws
(loosen only)
-------------,
press to
change
chart
time line
groove
Figure 2-2
If the battery is weak or not connected, the green LED will flash. If power is lost to the
cabinet, the LED will also flash. When replacing the 9-volt battery, use only an alkaline style
battery.
b. Changing the Chart Paper
1. Press the Change Chart button (#3) and hold it for 1 second until the pen begins to move
to the left of the chart. See Figure 2-2.
2. Remove the existing chart by unscrewing the center knob securing it.
3. Install the new chart, positioning it so that the correct time line coincides with the time
line groove on the chart plate.
4. Replace the center knob and screw it tightly against
the chart.
2-6

Forma Scientific, Inc.
c. Changing the Pen
1. Using a small flat blade screwdriver, loosen the 2 screws
holding the pen arm and remove the pen and arm as an
assembly.
2. Unsnap the plastic hinge securing the pen. Remove and
discard the old pen.
3. Install the new pen by snapping the hinge securely around
the pen arm. Figure 2-3
4. Re-install the pen assembly by sliding the pen arm under the screws, positioning the pen
tip in the time line groove. Tighten the screws.
5. Push the Chart Change button and hold it for 1 second until the pen begins to move back
onto the chart.
Note: Make sure that the pen is marking on the chart.
It may be necessary to
gently lift the pen onto the chart paper.
d. Calibrating the chart recorder
1. Place an accurate thermometer(s) in the chamber next to the recorder's probe(s). After about
three minutes, compare the thermometer with the chart recorder.
For 2 pen operations, also
compare the second thermometer.
Note: For 2 pen operations, first select the pen you wish to
calibrate. Hold down the #1 arrow for the red (#1)
pen
or the #2 arrow for the blue (#2) pen, until the
light goes out. Then adjust as necessary.
If an adjustment is necessary, press either the #1 or #2
button
to move the pen left or right. The button must be held
about five seconds before the pen begins
to move. Release the
buttonwhen the pen matches the thermometer.
Ef)~.3
~
o
Figure 2-4
2-7

Forma Scientific, Inc.
2.9 Controller Configuration
The controllers have been pre-configured at the factory. Reference copIes of the
Configuration records are included on the following pages.
The controller should not be re-configured without first
consulting Forma Scientific, Inc., Service Department at
1-800-848-3080.
2-8

Temperature Control Configuration fo~ 3940,3949,3980,3986,4940, & 4949
WaUow 982, Model: 982C-20KE-JRRR
Switch Configw:ation:
Main Boards
SWl ON
SW2 ON (This switch should remain in the OFF position until factory testing
has been completed.)
Out;put 2 Option Board.
SWl NA
SW2 NA
Out;put 3 Option Board
SWl NA
SW2 NA
Out;put 4 Option Board
SWl NA
SW2 NA
Input 1 Board
SW1
SW2
SW3
ON
ON
ON
Input 2 Board .
SW1 NA
SW2 NA
SW3 NA
Software Configuration:
Operations Menus
SYS: EilS· NA
Ent4 NA A3LO NA A4Hi NA
Ei25 NA
A2LO NA A3Hi NA Aut OFF
En13 OFF A2Hi
NA A4LO NA
PID: Pbl 2.0
dEl NA
It2 NA
dB 0.0
rE1 0.50 <:tl 5 rA2 0.25
Itl NA
Pb2 1.0
dE2 NA
rAl 0.19 rE2 0.25 <:t2 30
PROC: See Programming Sheets if required.
Setup Menus
InPt: In1
()"5
<:ALl •• rL2 NA <:AL2 NA
dEO 0.0
rtdl NA
rH2 NA
Hunt NA
rLl -20.0
Ftrl
2 LmL NA
rHi 80.0
1n2 NA LmH NA
·otPt:
Ot1 Ht
AL2
NA
LA13 NA
. SIL4
NA
PrO
NA·
LAt2 NA SIL3 .
NA Aout
NA
HyS1 0.1 SlL2
NA Ot4 NA Pr<:3
NA
0t2 CL
0t3
NA
AL4 NA ArL NA
Prc:2 NA
AL3 NA
HyS4
NA
ArH
NA
HyS2 0.1 HyS3
NA LAt4
NA
A<:AL NA
gLbL:
<:_F
NA
Anun ON
PtyP
ti PStr
StPt
Err nLA
loP -100 gSd 0 LOC
2*
Eil NO
HiP 100 POut Cont
Ei2
NA.
AtSP 90 IdSP NA
*LOC should be set at 0 until factory testing and calibration is complete.
*" This is a calibration factor and will vary from unit to unit.
<:OM: bAUd
9600 dAtA
70 PrOt FULL Addr
0
IntF NA
CONTCONF.XlS
Pagel Rev 1 8/12/96 CBG

Humidity Control Configuration for 3940, 3949, 3980, 3986, 4940, & 4949
Watlow 982,. Model: 982C-20KE-JRRR
Switch Configw;ation:
Main Boards
SWI ON
SW2 ON (This switch should remain in the OFF position until factory testing
---
Output 2 Option Board
SWI NA
. SW2 NA
Input I Board
SWI ON
SW2 ON
SW3 ON
has been completed.)
Output 3 Option Board
Output 4 Option Board
SWI NA
SW2 NA
. SWI NA
SW2 NA
Input 2 Board
SWI NA
SW2 NA
SW3 NA
Software Configuration:
OperatiOns Menus
SYS: . EilS NA
Ei2S NA
Ent3 NA
rEI 0.01
It1 NA
rAI 1.33
Ent4 NA
A2LO NA
A2Hi NA
cn
Pb2
rE2
5.0
2
0.00
A4Hi NA
Aut OFF
dB
rA2 0.00
dE2 NA
Ct2 30
PROG: See Programming Sheets if required.
Setup Menus
InPt: Inl 0-5
dEO ---=-0
rLl 30.0
rHi 95.0
OtPt::
Otl Ht
PrO "'="'N"""A-
HySl 1
Ot2CL
PrC2 """'N"-A-
HyS2 1
gLbL: C_F· NA
CAll ...
rtdl ":'N':"A~·-
Ftrl 2
In2 NA
AU NA
LAt2 NA
SIU NA
0t3 ALJ
AL3 Prl
HyS3 ---=-3
Anun ON
rL2 NA
rH2 NA
LmL NA
LmH NA
LAt3 nLA
SIL3 OFF
Ot4 NA
AU NA
HyS4 NA
LAt4 NA
PtyP ti
CAL2 NA
Hunt NA
SIlA· NA
Aout NA
PrC3 NA
ArL NA
ArH NA
ACAL NA
PStr StPt
o
Err nLA
loP -100 gSd
--"""0
Loe 2 *
Eil NO
Ei2 NA
HiP 100
AtSP 90
POut Cont
IdSP NA
.. LOC should be set at 0 until factory testing and calibration is complete.
.... This is a calibration factor and will vary from unit to unit.
COM: bAUd 9600 dAtA 70 PrOt FULL
IntF NA
Addr o
CONTCONF.XlS Page 2 Rev 1 .
8/12/96 CBG

Forma Scientific, Inc.
SECTION 3 -
CONTROL PANEL OPERATION
•
humldl!y
alarm
humidity conlrol
tempeon!rOl
@l II
ON ON
•
ON
dehumidify humidify
deflost retrigelatlM main power
fJ Forma Scientific C:::=============================:::::J
reach-In Incubator
Figure 3-1
Model 391113913, Control panel
3.1 Main Power Switch and Indicator Light (Refer to Figure 3-2)
The main power switch controls power to the incubator. The main power indicator
lights when the power switch is on and the unit is receiving power.
3.2 Refrigeration Switch and Indicator Light (Refer to figure 3-2)
The refrigeration switch controls power to the refrigeration system. The
refrigeration indicator lights when the refrigeration switch is on and the compressor is
receiving power.
3.3 Defrost Switch and Indicator Light (Refer
to Figure 3-2)
The defrost switch controls power to the defrost system. The defrost timer
is
factory-set to provide two I5-minute defrost cycles during a twenty-four hour period.
3-1

Forma Scientific, Inc.
The defrost switch must be turned on when the temperature
setpointis 100
C, orbelow.
The defrost indicator lights when the defrost switch is on and the incubator is in a
defrost cycle.
• heat
cool
tempcontml
et.nder temp
defrost refrigeration main power
3.4 Overtemp Safety Control,
Indicator Light and Audible
Alarm (Refer
to Figure 3-2)
The overtemp safety
thermostat should be set
slightly above the operating
temperature
of the incubator.
In the event
of an overtemp
condition, the overtemp
safety thermostat will:
1. Activate the audible alarm
and the overtemp
___ ---"I reach-in incubator
indicator light.
Figure 3-2
Temperature Controls Detail
2. Interrupt power to the heaters and maintain the temperature at the overtemp control
point.
The overtemp control is not directly calibrated. The numbers (0 to 10) on the dial
are
for reference only and do not correspond to any specific temperature. If an overtemp
condition occurs, the cause
of the problem must be determined and corrected before normal
operation under the main temperature controller can be resumed.
3-2

Forma Scientific, Inc.
3.5 Undertemp Safety Control, Indicator Light and Audible Alarm
(Refer
to Figure 3-2)
The undertemp safety thermostat should be set slightly lower than the operating
temperature
of the incubator. In the event of an undertemp condition, the undertemp
safety thermostat will:
1. Activate the audible alarm and the undertemp indicator light.
2. Interrupt power
to the refrigeration system and maintain the temperature at the
undertemp control point.
The undertemp control is not directly calibrated. The numbers (0
to 10) on the dial
are for reference only and do not correspond
to any specific temperature. If an
undertemp condition occurs, the cause
of the problem must be determined and corrected
before normal operation under the main temperature controller can
be resumed.
3.6 Humidify Switch and
Indicator Light (Refer to
Figure 3-3)
The humidify switch
controls the power
to the
humidification system circuit.
The heaters will operate only
if
there is a sufficient amount of
water in the humidification
system. The humidity indicator
lights when the humidify switch
IS on.
Figure 3-3
Humidity controls detail
3.7
Dehumidify Switch and Indicator Light (Refer to Figure 3-3)
When the dehumidify switch is on, power to the humidification system heater"s are
interrupted, and the refrigeration system comes on to provide control for drying. The
dehumidify light comes on when the dehumidify switch is on. When a defrost cycle occurs,
the dehumidify light may cycle on and
off to reflect the action ofthe humidity controller. The
dehumidify switch should be on when: 3-3
L! U U I.f humidify
;: E3 alarm
~~
~8
hUmidity control
{8
ONI"''t'%:
ill.~
~
dehumidify humidify
r= Forma Scientific .---~-