GSi HF Series User manual

PNEG-236
Humidistat-Thermostat
Models: HF-XXXX
Owner’s Manual
PNEG-236
Version: 2.0
Date: 11-16-22

2PNEG-236 Humidistat-Thermostat
All information, illustrations, photos, and specifications in this manual are based on the latest
information available at the time of publication. The right is reserved to make changes at any
time without notice.

Table of Contents
PNEG-236 Humidistat-Thermostat 3
Contents
Chapter 1 Safety .....................................................................................................................................................4
Safety Guidelines .................................................................................................................................. 4
Cautionary Symbols Definitions ............................................................................................................ 5
Safety Cautions ..................................................................................................................................... 6
Safety Sign-Off Sheet ......................................................................................................................... 12
Chapter 2 Safety Decals ......................................................................................................................................13
Chapter 3 General Installation ............................................................................................................................15
Installation Instructions ........................................................................................................................ 15
Chapter 4 Installation of TopDry High-Low Thermostat ..................................................................................16
Installation Instructions ........................................................................................................................ 16
Chapter 5 Operation ............................................................................................................................................17
Temperature Control ........................................................................................................................... 17
Humidity Control .................................................................................................................................. 17
Chapter 6 Operation and Service .......................................................................................................................18
High-Low Temperature Control ........................................................................................................... 18
Humidistat-Thermostat Service ........................................................................................................... 18
Chapter 7 Parts List .............................................................................................................................................19
Humidistat-Thermostat Parts (HF-7511) ............................................................................................. 19
Low-Temperature Humidistat-Thermostat Parts (HF-7515) ................................................................ 20
High-Low Humidistat-Thermostat Parts (HF-7516) ............................................................................. 21
Chapter 8 Wiring Diagrams .................................................................................................................................22
Humidistat-Thermostat Wiring ............................................................................................................. 22
Thermostat Wiring ............................................................................................................................... 23
Humidistat Wiring ................................................................................................................................ 24
High-Low Thermostat Wiring ............................................................................................................... 25
Chapter 9 Mounting Template ............................................................................................................................26
Chapter 10 Warranty ............................................................................................................................................27

4PNEG-236 Humidistat-Thermostat
1. Safety
Safety Guidelines
Safety guidelines are general-to-specific safety rules that must be followed at all times. This manual is
written to help you understand safe operating procedures and problems that can be encountered by the
operator and other personnel when using this equipment. Read and save these instructions.
As owner or operator, you are responsible for understanding the requirements, hazards, and precautions
that exist and to inform others as required. Unqualified persons must stay out of the work area at all times.
Alterations must not be made to the equipment. Alterations can produce dangerous situations resulting in
SERIOUS INJURY or DEATH.
This equipment must be installed in accordance with the current installation codes and applicable
regulations, which must be carefully followed in all cases. Authorities having jurisdiction must be consulted
before installations are made.
When necessary, you must consider the installation location relative to electrical, fuel and water utilities.
Personnel operating or working around equipment must read this manual. This manual must be delivered
with equipment to its owner. Failure to read this manual and its safety instructions is a misuse of the
equipment.
ST-0001-4

1. Safety
PNEG-236 Humidistat-Thermostat 5
Cautionary Symbols Definitions
Cautionary symbols appear in this manual and on product decals. The symbols alert the user of potential
safety hazards, prohibited activities and mandatory actions. To help you recognize this information, we
use the symbols that are defined below.
DANGER
WARNING
CAUTION
NOTICE
This symbol indicates an imminently hazardous situation
which, if not avoided, will result in serious injury or death.
This symbol indicates a potentially hazardous situation
which, if not avoided, can result in serious injury or death.
This symbol indicates a potentially hazardous situation which,
if not avoided, can result in minor or moderate injury.
This symbol is used to address practices not related to
personal injury.
This symbol indicates a general hazard.
This symbol indicates a prohibited activity.
This symbol indicates a mandatory action.
ST-0005-2

1. Safety
6PNEG-236 Humidistat-Thermostat
Safety Cautions
Use Personal Protective Equipment
Eye
Protection
Hearing
Protection
Hand
Protection
Head
Protection
Respiratory
Protection
Foot
Protection
Fall
Protection
• Use appropriate personal protective equipment:
• Wear clothing appropriate to the job.
• Remove all jewelry.
• Tie long hair up and back.
ST-0004-1
Follow Safety Instructions
• Warning: If the information in the manual is not followed exactly, a
fire or explosion can result, causing property damage, personal
injury or loss of life.
• Carefully read all safety messages in this manual and safety signs
on your machine. Keep signs in good condition. Replace missing or
damaged safety signs. Be sure new equipment components and
repair parts include the current safety signs. Replacement safety
signs are available from the manufacturer.
• Learn how to operate the machine and how to use controls properly.
Do not let anyone operate without instruction.
• If you do not understand any part of this manual or need assistance,
contact your dealer.
• Retain these instructions for future reference.
ST-0025-3

1. Safety
PNEG-236 Humidistat-Thermostat 7
Install and Operate Gas-Fired Equipment Properly
• Gas-fired equipment should be installed by a qualified pipe
fitter and must conform with local codes.
• For Canada: The equipment shall be installed in accordance
with the Natural Gas and Propane Installation Code, CSA
B149.1, or the Propane Storage and Handling Code, CSA
B149.2, or applicable provincial regulations, which should be
carefully followed in all cases. Authorities having jurisdiction
should be consulted before installations are made.
• For the United States: The equipment shall be installed in
accordance with the National Fuel Gas Code ANSI
Z223.1/NFPA 54.
ST-0016-2
For Your Safety
• If you smell gas:
- Do not try to light any appliance.
- Extinguish any open flames.
- Do not touch any electrical switch.
- Immediately call your gas supplier. Follow the gas supplier’s
instructions.
- If you cannot reach your gas supplier, call the fire department.
• The use and storage of gasoline and other flammable vapors and
liquids in open containers in the vicinity of this appliance is
hazardous.
• Improper installation, adjustment, alteration, service or maintenance
can cause property damage, injury or death. Read the installation,
operating and maintenance instructions thoroughly before installing
or servicing this equipment. Installation and service must be
performed by a qualified installer, service agency or the gas
supplier.
ST-0024-1
Maintain Equipment and Work Area
• Understand service procedures before doing work. Keep area
clean and dry.
• Never service equipment while it is operating. Keep hands, feet,
and clothing away from moving parts.
• Keep your equipment in proper working condition. Replace worn
or broken parts immediately.
ST-0003-1

1. Safety
8PNEG-236 Humidistat-Thermostat
Maintain Equipment and Work Area
• Understand service procedures before doing work.
• Keep area clean and dry.
• Do not service equipment while it is operating. Disconnect and
lock-out power and fuel supply before entering equipment or
before performing maintenance.
• Keep your equipment in proper working condition. Replace
worn or broken parts immediately.
• Depressurize the fuel train before disassembling for service.
• Allow the fan to operate for 20 minutes with the burner off to
purge products of combustion and to cool the components
before entering.
• Check regularly for any developing gas plumbing leaks. Do not
operate the dryer if any gas leak is detected. Shut down and
repair before further operation.
ST-0030-2
Exercise Caution When Drying Flammable Grains
• Be aware that some grains are highly flammable including, but
not limited to, rapeseed, canola, linseed, sunflower and milo.
• All grain and seed must be whole (minimal cracking or
crushing), clean, and dust free before drying.
• Avoid dust and chaff from being drawn into the fan and heater.
• To reduce risk of fire, keep the fan, heater, drying plenum, and
ducts clean at all times.
• In the event of a fire (or suspected fire):
1. Shut down the entire dryer.
2. Turn off the fuel at the tank or supply valve.
3. Shut off and lock electrical power.
4. Evacuate the area.
5. Call the fire department.
ST-0032-1

1. Safety
PNEG-236 Humidistat-Thermostat 9
Keep Hands Away from Moving Parts
• Do not operate the fan with electrical or mechanical guards
removed. Serious injury or death can result.
• Do not put hand or arm in fan. Rotating parts can crush and
dismember.
• Do not put any kind of tool inside the fan to clear debris while
the fan is operating. Damage to the equipment will result.
• Lock-out power source before making adjustments, cleaning,
or maintaining equipment.
ST-0020-2
Prevent Roof Damage Due to Vacuum Pressure
• Roof damage can result from excessive vacuum or internal
pressure from fans or other air moving systems. The manufacturer
does not warrant this type of roof damage.
• Adequate ventilation or “makeup air” devices must be provided
for all powered air handling systems.
• The manufacturer does not recommend the use of downward flow
systems (suction).
• Severe roof damage can result from any blockage of air
passages.
• Operating fans during high humidity or cold weather conditions
can cause air exhaust or intake ports to freeze.
ST-0028-2

1. Safety
10 PNEG-236 Humidistat-Thermostat
Sharp Edge Hazard
• This product has sharp edges, which can cause serious injury.
• To avoid injury, handle sharp edges with caution and always use
proper protective clothing and equipment.
ST-0036-2
Lifting Hazard
• Single person lift can cause injury.
• Use a mechanical lifting device to lift or move the equipment
during installation.
ST-0021-2
Install and Operate Electrical Equipment Properly
• Electrical controls must be installed by a qualified electrician
and must meet the standards set by the National Electric
Code, Canadian Electrical Code, and all local and state
codes.
• Lock-out power source before making adjustments, cleaning,
or maintaining equipment.
• Heater must be interlocked with an appropriately sized fan and
a thermostat must be installed for safe operation.
ST-0026-2

1. Safety
PNEG-236 Humidistat-Thermostat 11
Handle and Use Equipment Properly
• Equipment is intended for the use of grain drying only. Any
other use is a misuse of this equipment.
• The operating instructions in this manual pertain to the
common cereal grains as indicated. When drying any other
grain, contact GSI for additional recommendations.
• On LP fired units, set pressure regulator to avoid excessive
gas pressure applied to the burner during ignition and
operation. Do not exceed maximum recommended drying
temperatures.
• Equipment has sharp edges that can cause serious injury. To
avoid injury, handle sharp edges with caution and use proper
protective clothing and equipment at all times.
• All guards must be in place before and during operation.
Images of guards removed in this manual are for illustration
purposes only.
• Use caution when working around high-speed fans, gas
burners, augers and auxiliary conveyors which can start
automatically.
• Keep hands, feet, and clothing away from moving parts.
• Do not bypass any safety device or interlock.
• Do not enter the dryer or bin while it is operating.
• Do not operate in an area where combustible material will be
drawn into the dryer. ST-0029-2

1. Safety
12 PNEG-236 Humidistat-Thermostat
Safety Sign-Off Sheet
Below is a sign-off sheet that can be used to verify that all personnel have read and understood the safety
instructions. This sign-off sheet is provided for your convenience and personal record keeping.
Date Employee Name Supervisor Name
ST-0007

PNEG-236 Humidistat-Thermostat 13
2. Safety Decals
The safety decals on your equipment are safety indicators which must be carefully read and understood
by all personnel involved in the installation, operation, service and maintenance of the equipment.
To replace a damaged of missing decal, contact us to receive a free replacement.
GSI Decals
1004 E. Illinois St.
Assumption, IL. 62510
Phone: [phone]
A free replacement will be sent to you.
Location Decal # Decals Description
Located on the outside
of the door cover. DC-GBC-1A Warning Keep Clear of Augers
Located on the outside
of the door cover. DC-1224 Decal, Danger
High-Voltage (LG)
Located on the outside
of the door cover. DC-1225 Decal, Warning Rotating Blade
Located on the outside
of the door cover. DC-1227 Decal, Warning Fire (Small)
Rotating flighting could
kill or dismember.
Flowing material could
trap and suffocate.
Crusted material could
collapse and suffocate.
Keep clear of all augers.
DO NOT ENTER this bin!
If you must enter the bin:
1. Shut off and lock out all power.
2. Use a safety harness and safety line.
3. Station another person outside the bin.
4. Avoid the center of the bin.
5. Wear proper breathing equipment or respirator.
Failure to heed these
warnings could result in
serious injury or death.
DC-GBC-1AGSI GROUP,INC. 217-226-4421
WARNING
DANGERDANGER
DC-1224
Lockout power before
servicing.
Will cause serious injury or
death.
HIGH VOLTAGE
Couper/verrouiller le courant
avant l’entretien.
Causera de sérieuses
blessures ou la mort.
HAUTE TENSION
DC-1225
Stay clear of rotating
blade. Blade could start
automatically. Can cause
serious injury. Disconnect
power before servicing.
DC-1225 GSI Group 217-226-4421
WARNING
Flame and pressure beyond
door. Do not operate with
service door removed. Keep
head and hands clear. Can
cause serious injury.
DC-1227
WARNING
GSI Group 217-226-4421

2. Safety Decals
14 PNEG-236 Humidistat-Thermostat
Roof Damage Warning and Disclaimer
The manufacturer does not warrant any roof damage caused by excessive vacuum or internal
pressure from fans or other air moving systems. Adequate ventilation and/or “makeup air” devices
should be provided for all powered air handling systems. The manufacturer does not recommend
the use of downward flow systems (suction). Severe roof damage can result from any blockage of
air passages. Running fans during high humidity/cold weather conditions can cause air exhaust
or intake ports to freeze.
Excessive vacuum (or pressure) may
damage roof. Use positive aeration
system. Make sure all roof vents are
open and unobstructed. Start roof
fans when supply fans are started.
Do not operate when conditions exist
that may cause roof vent icing.
DC-969
CAUTION
GSI Group, Inc. 217-226-4421

PNEG-236 Humidistat-Thermostat 15
3. General Installation
Figure 3A 24" is the approximate distance from the edge of the transition to the edge
of the humidistat installation.
Installation Instructions
Standard electrical safety practices and codes should be used when installing the Humidistat-Thermostat.
Refer to the National Electric Code Standard Handbook by the National Fire Protection Association.
A qualified electrician should make all wiring installations.
1. The Humidistat-Thermostat should be mounted on the side of the bin wall between the foundation and
the drying floor. It should be installed approximately 24" from the right side of the transition as shown
in
Figure 3A .
2. Use the template on Page 26. With these instructions, drill only the holes necessary for the particular
model. (NOTE: For humidistat to operate properly optional cutout must be used.)
3. Caulk the top and sides of the plastic housing using roll caulking supplied with the unit. Do not caulk
the bottom side of housing so moisture can escape.
4. Carefully insert sensing probes through bin wall and secure housing to wall using self-drilling screws
provided. Be careful not to overtighten the screws. Damage to housing could result.
5. Make wiring connections to heater as shown in heater Owner’s manual.
Always disconnect and lock out power before working on or around heater.

16 PNEG-236 Humidistat-Thermostat
4. Installation of TopDry High-Low Thermostat
The High-Low thermostat is designed for use with the GSI TopDry crop dryer units. It comes with one
thermostat which is adjustable and cycles the heater from high to low flame. The High-Low thermostat also
comes with a thermometer for monitoring the plenum temperature.
Installation Instructions
1. Locate the mounting position of the thermostat as shown in Figure 4A.
2. Use the template on Page 26. With these instructions, drill only the holes necessary for the particular
model.
3. Apply rope caulk to sides and top of the plastic housing. Leave bottom open to let moisture escape.
4. Secure housing to sidewall using self-drilling screws supplied. Be careful not to overtighten.
Overtightening may cause the housing to crack.
5. Connect the black and white wires to the terminals marked bin High-Limit (3rd and 4th terminal bottom
left hand terminal strip) on fan and heater safety circuit board.
6. Connect the green and red wires to the terminals marked cycle (8th and 6th terminal bottom left hand
terminal strip) on fan and heater safety circuit board.
Figure 4A Placement of the TopDry High-Low Thermostat

PNEG-236 Humidistat-Thermostat 17
5. Operation
Temperature Control
1. Turn the fan unit ON and let it run 3 to 5 minutes to equalize temperature under the bin.
2. Set bypass switch to the “HUMIDISTAT OFF” position. This setting allows the unit to run based on
the temperature only.
3. Rotate the thermostat knob clockwise to the warmest position.
4. Open the gas valves to the heater and turn the heater ON. Set heater gas pressure to a moderately
high setting (5 to 10 PSI).
5. Monitor the thermometer on the thermostat housing. When the thermometer comes up to the desired
temperature, slowly turn the thermostat knob counterclockwise until the heater cycles OFF.
6. If the unit does not reach the desired temperature, gradually increase the gas pressure until the
temperature rises to the desired level.
7. Watch the unit run through several cycles and make any final adjustments. (NOTE: The unit should
be on approximately 80% of the time. If not adjust the gas pressure.)
8. Significant changes in outside air temperature may require readjustment of the gas pressure.
Humidity Control
1. Set bypass switch to the “HUMIDISTAT ON” position. This setting allows the unit to run based on
temperature and humidity.
2. Set the thermostat (Humidistat-Thermostat units only) to the maximum temperature desired. This
allows the thermostat to function as a High-Limit control only. See above Temperature Control for
setting the thermostat.
3. Set the humidistat to the desired relative humidity level you want to maintain under the drying floor.
The heater will cycle on above this relative humidity and OFF when this level is reached.
4. Use the equilibrium moisture chart below as a guide for setting the humidistat.
Equilibrium Moisture Chart (Shelled Corn)
Boxed area indicates safe moisture for normal winter storage of shelled corn at 15%. Grain
to be stored through the summer or long term, needs to be 1 to 3 points dryer.
Air
Temperature
(F)
Relative Humidity - Percentage (%)
35 40 45 50 55 60 65 70 75 80 85 90 95 100
20° 11.2 11.7 12.7 13.7 14.5 15.1 16.2 17.1 18.0 19.6 21.2 23.5 25.8 29.1
30° 10.8 11.3 12.2 13.1 13.9 14.6 15.5 16.4 17.4 18.7 20.2 22.5 25.0 28.3
40° 10.5 11.0 11.7 12.5 13.3 14.0 14.8 15.5 16.6 17.8 19.4 21.5 24.2 27.5
50° 10.1 10.6 11.3 12.0 12.7 13.3 14.1 14.8 15.8 16.9 18.6 20.5 23.4 26.7
60° 9.7 10.2 10.9 11.6 12.1 12.7 13.4 14.2 15.0 16.0 17.8 19.5 22.6 25.9
70° 9.0 9.7 10.4 11.1 11.5 12.0 12.8 13.5 14.5 15.4 16.8 18.5 21.3 24.5
80° 8.3 9.1 9.8 10.5 10.8 11.2 12.1 13.0 13.9 14.8 15.8 17.4 20.0 22.8

18 PNEG-236 Humidistat-Thermostat
6. Operation and Service
High-Low Temperature Control
1. Turn fan unit ON and let it run 3 to 5 minutes to equalize temperature under the bin.
2. Rotate the thermostat knob clockwise to warmest position.
3. Open gas valves (including Low-Fire valve) to the heater and turn the heater ON. Set heater gas
pressure to a moderately high setting (5 to 10 PSI).
4. Monitor the thermometer on the thermostat housing. When the thermostat comes up to desired
temperature, slowly turn the most at knob counterclockwise until heater cycles to Low-Flame.
5. If the unit does not reach desired temperature, gradually increase the gas pressure until the
temperature rises to the desired level.
6. Adjust the Low-Fire valve so that the temperature drops until the unit cycles back to High-Flame.
7. Watch the unit run through several cycles and make any final adjustments. (NOTE: The unit should
cycle approximately two times per minute. If not adjust gas pressure.)
8. Significant changes in outside air temperature may require readjustment of gas pressure.
NOTE: If temperature of Low-Flame exceeds thermostat settings (above normal outside temperatures)
unit will cycle from Low-Flame to OFF. (TopDry units will shut down completely.)
Humidistat-Thermostat Service
GSI thermostats are designed and built to withstand the harsh conditions usually found in drying bins.
A yearly preventative maintenance inspection may extend the life of the heating controls many years.
1. Remove the mounting screws from the thermostat housing and remove the housing from the bin wall.
2. Carefully remove the back panel from the housing. (It may be necessary to cut caulking.)
3. Blow out any dust or dirt that may have collected inside the housing.
4. Inspect the wiring for any loose connections, or rodent and insect damage.
5. Replace the back panel and caulk the corners to help seal the unit.
6. Re-install the unit on the bin wall.
Figure 6A
Always disconnect and lock out power before working on or around heater.
The Airstream Humidistat-Thermostat is mounted
on the lower right side of the grain bin’s transition.
This allows for easy service and operation.

PNEG-236 Humidistat-Thermostat 19
7. Parts List
Humidistat-Thermostat Parts (HF-7511)
Ref # Part # Description
1HF-7519 Enclosure, Thermostat Flat Body
2HH-1432 Thermostat, 70°F-190°F
3HH-1433 Humidistat, H4600A1004
4HH-1434 Gauge, 83KB Pressure Gauge
5HH-1435 Thermometer, 99-4 20-220 to be Dual Scale (F/C)
6HH-1436 Plug, Screen
7D03-1475 Knob, Plastic 0.250 D-Shaft Push ON 1230-K
8HH-2089 Plug, Plastic 2.625" Diameter Tapered
9HH-1442 Switch, SPST 10A-125V Toggle
10 HF-7108 Thermostat Cover
11 HH-7032 Grommet, Rubber Split 1.44" x 0.5"
12 HH-7029 Tube, Shrink 1/2"
13 HF-7110 Humidistat Perf. Cover

7. Parts List
20 PNEG-236 Humidistat-Thermostat
Low-Temperature Humidistat-Thermostat Parts (HF-7515)
Ref # Part # Description
1HF-7519 Enclosure, Thermostat Flat Body
2HH-3974 Thermostat, 80°F-140°F
3HH-1433 Humidistat, H4600A1004
4HF-1434 Gauge, 83KB Pressure Gauge
5HH-3973 Thermometer, 40/140 LTD and Low-Temperature to be Dual Scale (F/C)
6HH-1436 Plug, Screen
7D03-1475 Knob, Plastic 0.250 D-Shaft Push ON 1230-K
8HH-2089 Plug, Plastic 2.625" Diameter Tapered
9HH-1442 Switch, SPST 10A-125V Toggle
10 HF-7108 Thermostat Cover
11 HH-7032 Grommet, Rubber Split 1.44" x 0.5"
12 HF-7110 Humidistat Perf. Cover