ESSICKAIR SI-500S Single Inlet Horizontal and Down Discharge Evaporative Air Cooler Owner’s Manual

July 10, 2024

ESSICKAIR SI-500S Single Inlet Horizontal and Down Discharge Evaporative

Air Cooler


  • Model : ESSICK SI-500S12
  • Type : Evaporative Air Cooler
  • Inlet : Single
  • Discharge : Horizontal And Down

Product Usage Instructions

Installation Guidelines:

  1. Ensure the unit is installed on a sturdy structure capable of supporting its weight.
  2. Check that the cooler circuit has a suitable breaker to support the full amperage.
  3. Plan a safe method for transporting the cooler without damage or injury.
  4. Do not connect power until installation is complete.
  5. Wear gloves and protective eyewear during installation or servicing.

Operation Safety:

  • Do not use with any Solid-state speed control device to prevent fire or electrical shock.
  • The cooler has an automatic thermally protected motor that can restart without warning if it shuts off.

Servicing Guidelines:

  1. Disconnect the unit from the power source before servicing to avoid unexpected startup.
  2. Avoid draining water onto the roof to prevent slipping or staining.
  3. If the motor shuts off due to thermal overload, investigate and resolve the issue promptly to prevent permanent damage.

Tools and Supplies Needed for Installation:

  • Pliers
  • Drill bits
  • Screwdrivers
  • Hammer
  • Adjustable wrenches
  • Duct tape
  • Tubing cutter
  • Caulk
  • 5/32 hex key wrench
  • Sheet metal screws
  • Level
  • ECR-6 wall switch
  • Electric drill
  • Safety glasses

Motor Mounting Instructions:

  1. Place the motor into the cradles ensuring they fit into the groove in the motor grommets.
  2. Secure the motor with the saddle clamps provided, avoiding overtightening.

Warning: Do not energize the cooler until the installation is complete.

Shop genuine replacement parts for ESSICK SI-500S12

Owner’s Manual Model #’s

  • SI-500S , SI-500D
  • SI-700D , SI-700S
  • SI-500S12 , SI-500D12
  • SI-700S12 , SI-700D12

SINGLE INLET Horizontal And Down Discharge Evaporative Air Cooler

Our Mission:
We Will Respond to Our Customers With High Quality Products and Service, While Eliminating Waste From Our Processes.

Evaporative Cooling
Evaporative cooling uses the principle of evaporation to lower the air temperature. Hot, dry air is passed through wetted filters and is converted to refreshingly cooled air. Essick Coolers make the best use of the evaporative process by controlling the flow of water, spreading the water evenly over the filters, and keeping a steady stream of cooled air entering your home. It is exhausted out open windows or doors, carrying heat, smoke and odors along with it. Essick evaporative coolers are 80% less costly to operate than refrigerated air conditioners.

Cautions : To prevent harm to yourself and others, and to avoid damage to your cooler, PLEASE follow these guidelines.


When Installing| When Operating| When Servicing
Make sure that unit is installed on a sound structure that will support the full operating weight of the cooler. See page 5.| Make sure that cooler circuit is equipped with a (slow blow) breaker large enough to support the full amperage of the cooler.| Be sure to disconnect unit from power source before servicing. If not, it can be turned on from inside the house and start unexpectedly.
Before attempting to transport cooler to the roof. Separate fan section from wet section to reduce weight. Always plan a safe method of transporting cooler to installation site without

damage to the cooler or injury to yourself.


To reduce the risk of fire or electrical shock, DO NOT use this fan with any Solid-state speed control device.


Never drain water onto your roof. Water residue could cause you to slip or may stain your roof.

Do Not connect power to cooler before installation is complete.| This cooler is equipped with an automatic thermally protected motor. If it shuts off on its

own for any reason, it can restart without warning.

| If the motor shuts off because of thermal overload,       check into    the problem

immediately.       If allowed to continue, permanent damage will occur.

Wear gloves and protective eyewear when installing or servicing.

Tools and supplies needed for installation

  • Pliers
  • Screwdrivers
  • Adjustable wrenches
  • Tubing cutter
  • 5/32 hex key wrench
  • Level
  • Electric drill
  • Drill bits
  • Hammer
  • Duct tape
  • Caulk
  • Sheet metal screws
  • ECR-6 wall switch
  • Safety glasses
  • Wiring supplies – It is recommended that a licensed electrician do all electrical work.
  • Ductwork – A local sheet metal shop can supply ductwork.
  • ¼” water line
  • Saddle valve or faucet adapter
  • Roof stand (if cooler is roof mounted)
  • Roof flashing and pitch


  1. Prepare duct to fit model used (500 series coolers 17 ¾” square; 700 series 19 ¾” square).

  2. Cut opening in wall or roof to fit duct. If wall studs or roof joists are cut, reinforce them.

  3. Mount the duct in the opening. The duct will fit inside the cooler opening. The duct length from roof to bottom of cooler should be a minimum of 4” at the closest point, so there is access to the water drain.

  4. Install flashing around roof opening to prevent water entry. Use pitch to seal the seams.

  5. Measure cooler and layout mounting location.

  6. Mount cooler to stand or pad. Cooler must be level front to back and left to right.
    Note : It is best that the fan section end of the cooler face up the roof to achieve a lower profile and allow better access to the drain.

  7. Be sure to securely fasten all four corners of cooler to stand or pad.

  8. Caulk duct to the cooler to prevent air leakage.

Motor mounting

Warning : Do Not energize the cooler until the installation is complete.

  1. Place the motor into the cradles. Be sure that the cradles fit into the groove in the motor grommets.
  2. Secure with the saddle clamps provided in the installation package. DO NOT OVERTIGHTEN.

Electrical connections

CAUTION : Disconnect all electrical power at the breaker or fuse box before you begin to install or service any cooler.

  • Wiring for this cooler must comply with any and all applicable codes. It is recommended that a licensed electrician install any required wiring.
  • To remotely operate this unit, use an ECR-6 switch. It is equipped with 2 cooling positions, 2 vent positions and a pump only position to wash or pre-wet the pads.
  • The junction box mounts in the corner post of the fan section. Receptacles are provided for the motor and pump.
  • All wiring connections must be made inside the junction box. See wiring diagram below.

Motor pulley installation

  1. Loosen both set screws on the pulley. Use 5/32” hex key Allen wrench.
  2. Slide the pulley onto the motor shaft with the threaded side out.
  3. Install the belt and align the motor pulley and blower pulley.
  4. Align the set screw on the motor side of the pulley with the flat portion of the motor shaft and tighten.

Motor pulley adjustment

  1. Turn the outside jaw of the motor pulley clockwise until the pulley is fully closed.

  2. Align the outside set screw with the nearest flat spot on the threaded portion of the pulley. This is the zero position.

  3. Turn the outside jaw of the pulley counterclockwise 3 full turns. Align set screw with a flat on the threaded portion of the pulley and tighten. This step will ensure that your cooler will run without overloading the motor. Further adjustment may be required.
    Warning: if set screw is tightened onto threads, damage will occur and pulley will no longer be able to be adjusted. When the installation is complete and all panels are in place, check the motor amperage using clamp-on type ammeter. Since all the cooler access panels must be in place to get a true reading, check amperage at a disconnect box, breaker or fuse box.

  4. Find out the amperage from the motor nameplate.

  5. Clamp ammeter around the incoming white lead.

  6. Start the cooler on HI VENT.

  7. If amperage is less than motor nameplate rating, loosen the outer set screw of motor pulley, then turn the outer jaw of the pulley clockwise ½ turn and tighten the outer set screw. Recheck the amperage and repeat step if necessary.

  8. If amperage is more than motor nameplate rating, loosen the outer set screw of motor pulley, then turn the outer jaw of the pulley counterclockwise ½ turn and tighten the outer set screw. Recheck the amperage and repeat step if necessary.

  9. Proper belt tension is crucial to efficient operation and motor and belt life. See the maintenance section for instructions on achieving proper belt tension.

Install overflow and drain

  1. Slide rubber washer onto drain bushing and place through hole in reservoir from the top side.
  2. Secure it from below with the lock nut. Make sure rubber washer does not twist while tightening, which could cause it to leak. Hand tighten first and then tighten ¾ turn further with proper tool. Do not over tighten.
  3. Thread the plastic overflow tube into the drain bushing and hand tighten until snug.

Note: If leakage occurs after reservoir is filled, further snug the fitting until leakage stops. Plumber’s tape or thread putty may be used if necessary.

Float valve installation

  1. Place the threaded portion of the Float Valve through the hole provided in the Corner Post from the inside.
  2. Slip the Fiber Washer over the threaded portion outside the corner post and secure with the Nut. Be sure the Float does not turn while you are tightening the Nut.
  3. Slip the Float Tube onto the float so that the key hole is just behind the water inlet and the float rod is able to move up and down freely. The object is to contain any spray.

Water line connection

  1. Find the closest outside water faucet, and install a Water Connection Kit (not included with cooler) as shown. If an exterior faucet is not available, locate the closest cold water pipe and install a saddle valve assembly.
  2. Route tubing to cooler. Place Compression Nut and Ferrule over end of tubing. Insert the tubing into float valve and tighten Compression Nut to secure.

Note : Tightening a compression fitting will cause that fitting to leak. It is best to secure the connections, turn on the water, and then snug the fitting until leaking stops.

Adjusting water level and float
In order for the float to shutoff the flow of water at the desired level, you must adjust the float.

  1. Fill reservoir to ½” below top of overflow tube.
  2. Bend float rod down, slightly, until adequate pressure is achieved and float shuts off completely.

Note : Never use “soft water” from water softening equipment. This water is very corrosive and will cause damage to your cooler. Using a water softener in conjunction with this cooler will void the warranty. Use of caustic cleaners or other harsh chemicals will also void the warranty.

Start-up inspection
Before starting the cooler, make sure all installations are correct. Be sure that:

  1. Cooler is grounded and electrical connections are safe and secure.
  2. Cooler is level and duct is sealed
  3. Blower wheel does not rub the housing.
  4. Water supply is turned on.
  5. Drain fitting and water connections are secure and do not leak.
  6. Float is adjusted to the proper level.
  7. Important : motor pulley is set at the correct diameter. If not, motor can overheat and fail.
  8. Belt tension is OK.
  9. Pulley alignment is OK.
  10. Check switch for proper operation.

ECR-6 switch operation

Switch setting| Blower motor| Pump
Off| Off| Off
Pump Only| Off| On
Low Vent| Low| Off
High Vent| High| Off
Low Cool| Low| On
High Cool| high| On


Problem Cause Solution

Motor cycles on and off

| Motor pulley set too large Excessive belt tension

Blower shat frozen

| Adjust motor pulley Adjust belt tension

Lubricate or replace bearings

Water draining from overflow| Float improperly adjusted Lime build up in float valve| Adjust float

Clean or replace float

Blower shakes| Belt or pulley loose| Adjust or tighten
Fails to start| No electrical power

Blown fuse or popped circuit breaker

| Check power Replace or reset
Not cooling| Water supply turned off

Blocked water distributor

| Check water supply

Clean distributor


Caution : turn off all electrical power to the cooler before opening or attempting service of any kind

The motor is equipped with automatic thermal protection. If it shuts off for any reason, it can start back up without warning!

Occasionally inspect your cooler for leaks, loose belt, blocked water lines, correct belt alignment or excessive residue build up on the pads.

  • Belt tension
    At the proper tension, the belt will deflect ½” to ¾” when 3 to 5 pounds of pressure is applied to the belt approximately half way between the blower and motor pulleys. Adjust the belt tension using the motor bracket do not change the diameter of the pulley in order to adjust the belt tension.

  • Lubrication
    Lube the oil cups on the blower bearing. Use SAE20 or SAE30 Non-Detergent oil. Oil the blower motor only if oil holes exist.

  • End of season

1. Drain and clean the reservoir. Do not get water on the blower motor or pump motor.
2. Remove the belt and hang it from the motor pulley.
3. Remove the pads and clean carefully.
4. Remove water distributor and hose out with garden hose. Use a small nail to clean any deposits from the water holes.
  • Pad Replacement
    Lime build up can occur in the water reservoir and on the pads. Clean this off at least once per season. If any rust or bare metal spots occur on the cabinet, the metal should be sanded, primed and painted with good quality paint. 1/2″ to 3/4″

  • Deflection

1. Remove wet section top.
2. Remove water distributor assembly.
3. Remove and discard old pads.
4. Install new pad set. Refer to diagram below or pad installation instructions for correct orientation.
5. Ensure that water distributor pad is centered over cooler pads.
6. Carefully replace water distributor; ensure pads are not damaged while replacing assembly.
7. Replace wet section top.

Model| Weight

Dry                                                        Operating

SI500-S| 153| 224
SI500-D| 153| 224
SI700-S| 184| 255
SI700-D| 184| 255

Replacement Parts

No.| Description| Descripti o n| Qty| SI500S| SI500D| SI700S| SI700D
1| Fan section| Seccion del abanico| 1| 70018| 70001| 70023| 70038
2| Access Panel| Panel de acceso| 2| 70005| 70005| 70027| 70027
3| Blower Housing| Caja del ventilador| 1| 70021| 70014| 70034| 70040
4| Blower Brace| Conjinette del ventilador| 2| 70151| 70045| 70151| 70045
5| Blower bearing| Abrazedera del ventilador| 2| 30289| 30289| 30288| 30288
6| Motor| Motor| 1| | | |
7| Motor pulley| Polea del motor| 1| 70170| 70170| 583041| 583041
8| Motor mount| Montaje del motor| 1| 70154| 70154| 70125| 70125
9| Blower Pulley| Polea del ventilador| 1| 583013| 583013| 30314| 30314
10| Blower wheel| Rueda del ventilador| 1| 30322| 30322| 70120| 70120
11| Blower belt| Banda del ventilador| 1| 582090| 582009| 4L690| 582001
12| Set collar| Collar fijo| 1| 524331| 524331| 524331| 524331
13| Blower shaft| Eje del ventilador| 1| 30238-02| 30238-02| 30238-01| 30238-01
14| Float valve| Valvula flotadora| 1| 524198| 524198| 524198| 524198
15| Float tube| Tubo flotador| 1| 70132| 70132| 70132| 70132
16 | Wet section top| Tapa de seccion del agua| 1| 70009| 70009| 70009| 70009
| Wet section housing| Estructura de la seccion de agua| 1| 70006| 70006| 70028| 70028
18| Water hose| Manguera del agua| 1| 70196| 70196| 70197| 70197
19| Pump bracket| Abrazadera de la bomba| 1| 70067| 70067| 70067| 70067
20| Pump| Bomba| 1| 506674| 506674| 506674| 506674
21| Water distributor tube| Tubo del distribuidor del agua| 1| 70116| 70116| 70116| 70116
22 | Water distributor| Distribuidor del agua| 1| 70043| 70043| 70043| 70043
| Pad media set| Juego de filtros| 1| 70054| 70054| 70055| 70055
24 | Water shield set| Juego de protectores del agua| 1| 70095| 70095| 70098| 70098
| Pad support tray| Bandeja para sostenerlos filtros| 1| 70010| 70010| 70010| 70010
26| Overflow kit| Equipo de desbordimiento| 1| 70613| 70613| 70613| 70613
27 *****| Reservoir| Deposito| 1| 70053| 70053| 70053| 70053
28| Inlet Screen| Alambrera| 1| 70012| 70012| 70031| 70031
29| Electrical junction box| Caja de union electrica| 1| 70130| 70130| 70130| 70130
30| Motor plug| Enchufe del motor| 1| 595098| 595098| 595098| 595098
31| Pump plug| Enchufe de la bomba| 1| 595121| 595121| 595121| 595121
32| Blower cutoff| Tapon de la caja del ventilador| 1| 504280| 504280| 70124| 70124
33| Water distributor pad| Filtros del distribuidor del agua| 1| 70155| 70155| 70155| 70155

Speak with Essick Air Products representative for specific motor requirements.

For units with 12” media, refer to table below for Wet Section parts.

No.| Description| Descripti o n| Qty| SI500S- 12| SI500D- 12| SI700S- 12| SI700D- 12
16| Wet section top| Tapa de seccion del agua| 1| 70877| 70877| 70877| 70877
| Wet section housing| Estructura de la seccion de agua| 1| 70907| 70907| 70879| 70879
22| Water distributor| Distribuidor del agua| 1| 70872| 70872| 70872| 70872
| Pad media set| Juego de filtros| 1| 70912| 70912| 70875| 70875
24| Water shield| Juego de protectores del agua| 2| 70909| 70909| 70874| 70874
| Pad support tray| Bandeja para sostenerlos filtros| 1| 70887| 70887| 70887| 70887
27*| Reservoir| Deposito| 1| 70871| 70871| 70871| 70871

Limited Warranty

This warranty is extended to the original purchaser only of an evaporative cooler installed and used under normal conditions. It does not cover damages incurred during shipping or through accident, neglect, or abuse by the owner. Essick Air Products does not authorize any person or representative to assume any other or different liability in connection with this product.

Terms and conditions of warranty
This warranty includes lifetime limited coverage on water reservoir against any leakage due to defects in material. From date of installation, if any original component part provided by Essick Air Products fails due to defect in material or factory workmanship only, Essick Air Products will provide the replacement parts as follows:

  • Cabinet components for one year from date of installation
  • Evaporative media for five years from date of installation

Exclusions from this warranty

  • Essick Air Products is not responsible for incidental or consequential damage resulting from any malfunction.
  • Essick Air Products is not responsible fo r any damage occurring from the use of water softeners, chemicals, descale material, or if a higher horsepower motor than what Essick Air Products recommends is used in the unit.
  • Essick Air Products is not responsible for th e cost of service calls to diagnose cause of trouble, or labor charge to repair and/or replace parts.

How to obtain service under this warranty
Contact the Dealer where you purchased t he evaporative cooler. If for any reason you are not satisfied with the response for the Dealer, contact Customer Service Department: Essick Air Products Inc. 5800 Murray Street, Little Rock, Arkansas 72209. 1-800-643-8341.


Q: Can I use a Solid-state speed control device with this cooler?
A: No, using a Solid-state speed control device can lead to fire or electrical shock. It is advised not to use one with this cooler.

Q: What should I do if the motor shuts off due to thermal overload?
A: If the motor shuts off due to thermal overload, investigate the issue immediately to prevent permanent damage.

Q: What safety precautions should I take during installation?
A: Ensure that the cooler is installed on a sound structure, wear gloves and protective eyewear, and do not connect power until installation is complete.


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