World Chemical SUBMERSE YD-GWN Series User manual

SUBMERSIBLE MAGNET DRIVE PUMP
SUBMERSE
YD-5002GWN1
INSTRUCTION MANUAL
Version: 230420

1
Preface
Thank you very much for purchasing World Chemical’s submersible magnet drive pump “SUBMERSE”.
To effectively use SUBMERSE for an extended period of time, it is necessary to operate correctly and
maintain as described in the instruction manual. Before using, read and understand the safety
precautions outlined in this manual.
TABLE OF CONTENTS
Warning ........................................................................................................................................................ 2
Caution......................................................................................................................................................... 3
Model / Specification.................................................................................................................................... 4
Outline Dimension........................................................................................................................................ 5
Features / Precautions in handling / Operating Temperature...................................................................... 6
Minimum required liquid level for operation / Example of installation / Model description.......................... 7
Usage ........................................................................................................................................................... 8
Check before operation................................................................................................................................ 9
Disassembly ..............................................................................................................................................11
Assembly.................................................................................................................................................... 12
Exploded view ............................................................................................................................................ 13
Troubleshooting.......................................................................................................................................... 14
Warranty / Repair .......................................................................................................................................15

2
Warning
Using with dangerous liquids or atmosphere
When transferring dangerous liquid using this pump, or using in potentially explosive atmospheres (only
explosion-proof type), observe the equipment standards set forth by law and make sure to perform daily
inspection to prevent liquid leakage. If the pump is operated under the abnormal conditions such as liquid
leakage, it may cause a severe accident, such as a physical injury, an explosion, or fire. Always comply
with instructions of the supplier or manufacturer of liquids.
Prohibited use of a damaged or modified pump
Using a damaged or modified pump may cause a physical injury, electric shock, or product failure. Such
usage will not be covered by our warranty.
Cautions on transporting and lifting the pump
Use the hoist bolts when lifting a pump. If a hoist bolt is not available, use a belt sling to lift the pump with
careful attention to the weight balance. Only a qualified person should perform this with a strong enough
sling. The lightest pump weighs approximately a minimum of 50lbs (23kg). Do not hand carry the pump as
much as possible, as it may cause an accident.
Prohibited work with the power ON
Do not perform inspection or disassembly of the pump or motor while the power is ON. Rotating parts can
cause physical injury. You can also be subject to electric shock. In addition to confirming the main power
is OFF, check the hand switch of the pump as an additional safety measure before performing any work.
Connection of a ground wire
Using the motor without a ground wire connected may cause an electric shock. A qualified person must
ground it according to the electric equipment technical standards and wiring regulations.
Protection of a power cord
Pulling, tucking, or damaging a power cord or motor lead wire may damage the cable, causing fire or an
electric shock. Install the terminal box cover in the designated position after wiring.
Installation of Ground Fault Interrupter (GFI)
If a ground-fault interrupter is not installed when using the pump, an electric shock may occur. Install a
ground-fault interrupter or overcurrent protective device to prevent electric accidents or motor damage.
Cautions on removing the pump
When removing the pump from pipes, close the suction and discharge pipe valves to ensure no spillage
occurs. Directly touching chemical liquid may be hazardous, and may cause severe injuries. Wear
protective equipment before starting work.

3
Caution
Prohibited use
Do not use the pump with other than as listed on the pump specifications or nameplate. Especially, check
the motor’s power supply specifications (phase, voltage, and frequency) before connecting. Incorrect
usage may cause a physical injury or damage of the filter pump or peripheral devices.
Restriction on users
Only knowledgeable experts of the pumps should handle and perform installation, wiring, operation, or
maintenance.
Cautions on unpacking
Check and confirm the proper side up when unpacking. When unpacking the crate,be careful with nails or
wood chips to avoid any injury.
Ventilation
If any object is placed around the pump, it can block ventilation, causing the motor to overheat.
When handling poisonous or odorous liquid, install the pump where sufficient ventilation is available, due
to risk of inhalation.
Repair and return
To request repair of a damaged pump, contact our sales representatives or your distributor.
When returning the pump using a carrier service or parcel delivery service, wash both inside and outside
of the pump with clean water, make sure no liquid residue is left, and wrap it with a plastic bag.
Resin parts
The pump consists of resin parts, so a strong impact may damage parts or lead to physical injury. Do not
strike the pump with any objects or climb on it. Additionally, install a pipe support to prevent a load being
directly applied to the pump.
Starting of the pump
Make sure to check the rotational direction when starting the pump for the first time. Open the suction and
discharge valves and ensure no liquid leakage near the pipe connection area. After air is released from
the pipes and liquid is filled within the pump, briefly start to check the rotational direction. If the direction is
reversed, in the three-phase power supply, switch two of the three cables. As a precaution, ensure the
power supply is disconnected before performing any work.
Disposal of the pump
When discarding used pumps, dispose of them as industrial waste following the applicable laws and
regulations after removing accumulated chemicals.

4
Protection measures for leakage
In case of liquid leakage from the damaged pump or pipe, take appropriate safety and protection
measures.
◼Model Description / Specification
Model: YD-5002GWN1
YD-5002GWN1-HP (High pressure version, Only 60Hz)
Type: Chemical Submersible Magnet Drive Pump
Name: SUBMERSE
◼Specification
Total head Capacity
5002GWN1 60Hz 8.3m (27ft)
200L/min
(52gpm)
5002GWN1-HP 60Hz 11.9m (39ft)
100L/min
(26gpm)
Model
Frequency
Output
Power
Discharge
bore
23kg
(50lbs)
Weight
200/220V/460V
60Hz
Standard Specification
50mm (2")
1.1kW
Pump
Motor
Main material
Carbon Fiber Reinforced
Polypropylene
Type
Dry three phase
induction motor
Bore
50A=2"
Insulator
H
Model
5002GWN
5002GWN-HP
Rated output
1.1kw=1.5HP
Frequency
60Hz
60Hz
Phase
3
Total head
Max
41
47
Pole
2
Standard
27
39
Rated
Voltage
60hz
460V (200V/220V)
Capacity
Max
87
80
Standard
52
26
Rated
Current
60hz
4.5A(4.75A/4.38A)
Others
Dimension
Outline
15" x 9.8" x 16" (H)
Starting
Current
60hz
23.1A(23.03/22.73A)
Height
Weight
50lbs
Method of Stating
Direct
Attached cable
2PNCT 4cores
Rotating speed
3410min-1
(3340/3390min-1)
1.25mm2x 10m (32ft)
Liquid temperature
(max)
140F (60℃)
Thermal protector
Built-in motor

5
◼Outline dimension
No. Part name Remarks No. Part name Remarks
1 Motor FC 15 Set bolt 92 CFR PP
2 Motor magnet Ferrite 16 Set bolt 52 CFR PP
3 Motor magnet key SS 17 Set bolt nut CFR PP
4 Motor magnet nut SS 18 O-ring for set bolt FPM / EPDM
5 Cab tire cable 2PNCT 19 Floating washer
PTFE (Only Ceramic
bearing)
6 Motor cover CFR PP 20 Standoff bolt HT, PVC
7 Impeller CFR PP 21 Strainer PP
8 Impeller magnet Ferrite 22 Sludge fence PP
9 Front bearing PTFE / Ceramic 23 Bottom plate PP
10 Rear bearing PTFE 24 50A Valve socket PVC
11 Separating board Ceramic
12
O-ring
for separating board
FPM / EPDM
13 Casing CFR PP
14 Pump shaft SiC
* When the temperature of the liquid is high (131F/ 55C degrees and more), do not use No. 24: Valve socket (PVC). If using a valve socket,
HT-PVC valve socket is recommended.
A-A
Elbow: Thread
Strainer
φ3

6
◼Features / Precautions in handling / Temperature to use
SUBMERSE is constructed of Carbon Fiber Reinforced Polypropylene and a corrosion resistant ceramic
shaft. Additionally, the structure is a magnet drive type which does not require a shaft seal, which makes
the submersible pump compatible with strong acid and strong alkaline liquids that the previous pumps
could not handle.
1. All the wet parts are made of corrosion resistant resin and ceramic.
2. The pump can be used for strong acid and alkaline liquids.
3. It is a magnet drive structure which does not require a shaft seal. Liquid will not enter the motor.
4. There are little consumables and parts are replaceable.
5. Operation of the pump is as simple as placing it in a tank. It also can be mounted in a hanging
position.
6. Easy grip for carrying, and durable construction ideal for emergency purpose.
7. A ceramic plate is used between the motor and pump chamber, which makes it resistant to both heat
and chemicals.
8. A thermal protector is incorporated. If motor overload is detected from any cause, the thermal
protector is activated to stop the motor.
◼Precautions in handling
1. Slurry will accelerate bearing wear. Especially when the pump is used in a sedimentation tank, mount
the pump to prevent slurry from entering the pump, or clean any slurry before reaching the pump.
(Replacement of the bearing is easy. Use a ceramic bearing on liquids with slurry.)
2. Completely submerge the pump to use. Operation with air may cause pump failure.
3. If the check valve is attached at the discharge pipe, air will not be released, which will cause dry
running. If you attach the check valve, install the air release pipe beneath to always release air.
4. If the pump is not completely submerged in liquid and exposed to air, the motor will not cool down,
causing a damage to the motor resin cover.
5. A liquid level gauge malfunction can cause dry running. Check before the operation.
6. Make sure to attach the strainer to the pump in order to prevent debris from entering, and always
clean it to be clog-free. If it is clogged, the pump may overheat.
7. When considering electric wiring, ensure the wiring gauge is adequate to prevent voltage drop.
8. When the liquid temperature is high (131F/55C degrees and higher), change the material of the valve
socket (PVC) at the discharge outlet. (High temperature- PVC is recommended.)
9. Do not use the pump for highly concentrated sulfuric acid (50% and more).
◼Operating temperature
YD-5002GWN1: 140 Fahrenheit / 60 Celsius (MAX.) Cable material: 2PNCT

7
◼Minimum required liquid level during operation / Example of
Minimum required liquid level for continuous operation is 16 inches (400 mm).
Keep the minimum liquid level during operation, enough to submerge the whole pump. (Liquid level for
continuous operation: 16 inches/400mm or higher from the pump’s bottom surface.) Operation below
the required liquid level, such as for dead head operation, should be less than 5 minutes.
Do not repeatedly run for less than 5 minutes.
Depending on the operational situation, the incorporated thermal protector may get activated to stop
the pump in order to protect the motor. In that case, stop the operation for a while. Check the pump
status and ensure the proper liquid level to resume the operation.
Minimum liquid level for operation is 5.1 inches (130 mm).
The minimum liquid level for operation is 5.1 inches/130mm from the pump’s bottom surface.
⚫Even with the proper operational liquid level, depending on the liquid surface condition, there is a
chance that the operation may be interrupted due to air entering.
⚫If the impeller of the pump runs with air, the rotating parts may be damaged.
◼Example of installation
To prevent water hammer, refer to the following image for pipe installation.
Model description
YD –50 02 GWN1 –CP –A D 6 2 –HP - V
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(1) Bore: 50 = 50A
(2) Motor output: 02 = 1.1kW = 1.5HP
(3) Main cover material: CFR PP
Pressure gauge
Sluice valve
Check valve
Air release pipe
(Always open slightly)
Min. liquid level for
continuous operation
(16 inches/400mm)
Operational min. liquid
level
(5.1 inches/130mm)

8
(4) Bearing material: R = PTFE A = Alumina Ceramic
(5) O-ring material: E = EPDM D = FPM
(6) Frequency: 5 = 50Hz6 = 60Hz
(7) Specific gravity: 1 = 1.1 3 = 1.3 5 = 1.5
(8) Impeller: No mark = Standard type HP = High pressure type
(9) Special mark: (Ex.) V = Non-standard voltage Z = With PVC cable sleeve
* When the special mark is other than above listed, it means a custom requirement by customer or special
specification with some modifications added.
◼Usage
1. To pump chemical liquids or wastewater from a deep or narrow tank.
2. To pump liquids that are easily aerated.
3. To pump chemical liquids from a sealed tank.
4. To circulate liquids in a tank.
5. To mix liquids in a tank or an equipment.
6. To pump or transfer liquids in an emergency.
Samples of usage
Pumping liquid from a
deep tank
Pumping easily aerated
liquid or from a shallow tank
Pumping liquid from a
narrow and deep tank
Scrubber system
(Washing system)
Using for a tank truck
For mixing

9
◼Check before operation
1. Electric wiring
Before starting operation, check the rotational direction. Connect U (red), V (white), W (black), and
ground (green) wires to start the pump. The rotational direction can be checked as follows:
1-(1) In reverse direction, the discharge amount will be 30% of what it would be in the forward
direction.
1-(2) When turning the switch ON while the pump lifted in water, it should be a counterclockwise
rotation observed from the above.
Note: In case of the reverse rotation, switch two of the three cables (Red, White, and Black).
2. Precautions in electric wiring
⚫Make sure to connect a green ground wire to a ground plate or bar before connecting the cab tire
cable to prevent electric shock.
⚫Never test the pump in the air. Generated heat may deform the pump and cause failure.
⚫Install a circuit breaker to prevent unexpected problems.
Note: To prevent electric shock or fire, the user is obligated to provide a circuit breaker
according to the industrial safety and health regulations and electric equipment technical
standards.
Red –U
<Cab tire cable side> White –V <Motor cable side>
Black –W
Green –Ground
Forward rotation
Reverse rotation

10
3. Voltage during operation
If voltage is low, current increases. This can cause the thermal protector to be activated as the
temperature of the stator increases. Low voltage causes pump performance failure. Use the pump
with the voltage within the specified range.
Note: Applicable voltage for this pump is within ±10％of the rated voltage.
4. Thermal protector (Protection Instrument)
When the temperature of the motor coil is near the maximum temperature limit from electrical or
mechanical reasons, motor burn protection function will be activated and stop the motor by cutting off
the electric circuit. Carefully investigate the cause which activated the thermal protector, remove that
factor, and resume the operation.
Note: Make sure to turn off the power before investigating. The thermal protector will
automatically resume.

11
◼Disassembly
1. Remove 4 set bolts (16) from the standoff bolts (20)
which are affixed to the casing (13).
2. The bottom board (23) with the standoff bolts (20) and
the strainer (21) are removed.
3. After removing the rest of the set bolts (15) (16), pull
the casing (13) forward to separate. The impeller (7) is
secured on the motor cover (6) through the separating
board (11).
4. Remove the O-ring for separating board (12), and
move the impeller (7) attached to the motor side magnet
(2) outward to remove.
⚫Do not disassemble the motor (including the cable). When maintenance of the motor is required,
contact your distributor.
Set bolt (16)
Casing (13)
Standoff bolt (20)
Strainer (21)
Bottom board (23)
Set bolt (15) (16)
Motor cover (6)
O-ring for separating board (12)

12
◼Assembly
1. Insert the O-ring for separating board (12) in the groove of the motor
cover (6).
2. Slide the impeller (7) from the side of the separating board (11) to
the center. Do not move the impeller (7) quickly, as the separating
board (11) could be damaged by impact caused when the impeller
(7) approaches to the motor magnet (2) as a result of magnetic
force.
3. Attach the standoff bolts (20) to the bottom board (23) and put the
casing (13) on the strainer (21). Attach the O-rings for set bolts (18)
to the standoff bolts (20).
4. Attach the O-ring for separating board (12) to the casing (13) and put
the parts assembled in the above procedures 1 & 2. Insert the
bearing of the impeller (7) so that the inner diameter fits to the outer
diameter of the pump shaft (14).
5. Insert the set bolts (15) (16). Install the O-rings for set bolts (18) to
the nuts (17). Attach the nuts for the set bolts (17) first, then attach
the standoff bolts (20).
⚫The tightening torque is 8N・m to tighten the set bolts (15) (16).
Tighten opposing bolts diagonally to fix.
Motor side magnet (2)
O-ring for separating board (12)
O-ring for set bolts (18)

13
◼Exploded view
6
2
15
16
18
20
23
17
18
21
7
12
11
12
4
5

14
Troubleshooting
1. Insufficient pumping and discharge amount
2. Overheating Motor
3. Pump vibration
Insufficient pumping and discharge amount
Insufficient discharge amount
No pumping when discharge valve
is open
No pumping when priming water is
fed into the pump
Pump
rotates in
reverse
Air trapped
in suction
pipe
Resistance
in discharge
pipe
Air entering
from suction
pipe or
connection
area
Step-out of
magnet
coupling
Insufficient
amount of
priming
water
Foreign
object in
suction pipe
Switch
motor wiring
Inspect
suction pipe
Remove
foreign
object from
discharge
pipe and
check for
pipe damage
Inspect
connection
area of
suction pipe.
Check liquid
level of pit
tank
Check
inside the
pump for
foreign
objects.
Check that it
is not in an
overloaded
state.
Supply
priming
water.
Discharge
all air in the
pump.
Clean
suction pipe
Overheating motor
Excessive output
Check if specific gravity and
viscosity of liquid used match the
specifications
Check if motor voltage and
frequency match the specifications
Operating temperature is high
Lower the operating temperature
Pump vibration
Unstable
installation
location
Loose bolts
on the pump
Foreign
object in
suction pipe
Worn pump
bearing
Damaged
pump shaft
Pump impeller
in contact with
stationary part
Worn motor
bearing
Re-install it
Tighten bolts
Remove
foreign
objects and
clean
Replace
pump
bearing
Replace
pump shaft
Replace
impeller
Replace
bearing or
motor
Min. liquid level is low
Increase to min. liquid level

15
STANDARD ONE-YEAR LIMITED WARRANTY
FOR SALES MADE ONLY IN THE UNITED STATES, CANADA
This limited warranty completely replaces the warranty issued by World Chemical Co., Ltd.
relating to the below described Pumps.
WCUSA warrants its Magnetic Drive Pumps, Self-Priming Pumps, Oil Skimmer Systems, Vertical
Pumps and Submersible Pumps (“Pumps”) against defects in materials and workmanship for one
year from the date of WCUSA’s invoice to you for the affected Pump. This warranty requires you
to return the Pump to WCUSA.
If there is a manufacturing defect, WCUSA will replace or repair the Pump with new or rebuilt parts
at no charge to you. Please return the Pump to: World Chemical USA, 25691 Atlantic Ocean Dr. Unit
B-15 Lake Forest, CA 92630.
When returning the Pump, include your name, address, daytime telephone number, and a description
of the problem. No warranty work can be performed without this information.
Properly pack the Pump (preferably in the original carton) to prevent damage to the Pump in transit.
The repaired or replaced Pump will be warranted for a period equal to the remainder of the original
one-year warranty.
All replaced Pumps, parts and components, shall become the property of WCUSA
This Limited Warranty does not cover: (a) defects or damage resulting from accident, misuse,
abnormal use, abnormal conditions, improper storage, exposure to dirt, neglect, or unusual physical,
electrical or electromechanical stress; (b) scratches, dents and cosmetic damage, unless caused by
WCUSA; (c) Pump that has the serial number removed, defaced, damaged, altered or made illegible;
(d) ordinary wear and tear; (e) defects or damage resulting from the use of Pump in conjunction or
connection with other equipment not furnished or approved by WCUSA; (f) defects or damage
resulting from improper testing, operation, maintenance, installation, service, caused by the use of
unauthorized parts of service; (g) defects or damage resulting from external causes such as collision
with an object, fire, flooding, dirt, windstorm, lightning, earthquake, exposure to weather conditions,
or improper use of any electrical source; (h) irregularities or breakdowns due to chemical or
hydrodynamic corrosion by liquid. We do not warrant the chemical resistance of the Pump to any
chemical or to corrosion.
You will be responsible for paying for your own shipping costs for delivering the Pump to us. If we
determine the Pump is covered by this warranty, we will return the new or repaired Pump to you at
our expense. If we determine that the Pump is not covered by this warranty, we will return it at
your expense.

16
WCUSA does not warrant accessory components, including, but not limited to, Impeller (including
mouth ring and bushing), Rear Casing set (include shaft), O-Ring for Casing and other consumable
parts.
REPLACEMENT OR REFUND OF THIS PUMP AS PROVIDED UNDER THIS LIMITED
WARRANTY IS BE YOUR EXCLUSIVE REMEDY.
WE ARE NOT RESPONSIBLE OR LIABLE FOR ANY LOSS, INCONVENIENCE OR DAMAGE,
WHETHER SPECIAL, DIRECT, INCIDENTAL, CONSEQUENTIAL, OR OTHERWISE, AND
WHETHER KNOWN OR SHOULD HAVE BEEN KNOWN TO US, INCLUDING LOST
PROFITS, GOODWILL, DAMAGE TO OR REPLACEMENT OF OTHER PUMPS AND
PROPERTY AND PERSONAL INJURY RESULTING FROM ANY BREACH OF WARRANTY,
THE INABILITY TO USE THE PUMP OR UNDER ANY LEGAL THEORY IN CONTRACT OR
TORT. THESE WARRANTIES AND REMEDIES ARE YOUR SOLE AND EXCLUSIVE
WARRANTIES AND REMEDIES IN CONNECTION WITH THE SALE AND USE OF THE
PUMP. NO OTHER WARRANTIES, ORAL OR WRITTEN, EXPRESS OR IMPLIED, ARE
GIVEN. OUR LIABILITY IS LIMITED TO THE ACTUAL PURCHASE PRICE YOU PAID TO
THE RETAIL SELLER OF THE DEFECTIVE PUMP. EXCEPT TO THE EXTENT PROHIBITED
BY LAW, ANY IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE LIMITED IN DURATION TO THE DURATION
OF THIS LIMITED WARRANTY.
Some states do not allow the exclusion or limitation of implied warranties or liability for incidental
or consequential damages, or do not allow a limitation on how long an implied warranty lasts, so the
above limitations or exclusions may not apply to you. You are advised to contact applicable state
laws for a full determination of your rights. This warranty gives you specific legal rights, and you
may have other rights which vary from state to state.
No dealer, agent or employee is authorized to make any modification, extension, change or
amendment to this warranty. This warranty may not be assigned without the prior expenses written
approval of WCUSA.

17
1. Repair
If any irregularity is detected during operation, stop the pump and check it. Refer to the section on
“Troubleshooting”.
1. To request a repair service, ask your supplier or us.
2. Before requesting a repair service, read this instruction manual carefully and check it, again.
3. When requesting a repair service, provide the following information:
⚫Pump model and serial number
⚫The period of use and the condition
⚫The failure parts and the condition
⚫Type of liquid (name, specific gravity, temperature, any slurry or not)
Clean the inside of the pump adequately when returning it, because if the residual liquid leaks out during
shipment, it creates a hazardous condition.
Use names in the parts table (P6) to order for replacement or spare parts. Nevertheless, also provide the
part number and the material just in case.
Model:
Purchase date:
Serial No.
Date to start:
Supplier:
Notice: When repairing, consult your supplier. Wash the wet parts kit for the returned pump
adequately and pack it.

18
WORLD CHEMICAL CO., LTD. / Japan
Head Office / Overseas department
3F., ANTEX24, 1-1-14, Taito. Taito-ku, Tokyo, 110-0016 Japan
TEL : [phone] FAX : [phone] (Head office)
TEL : [phone] FAX : [phone] (Overseas Department)
Osaka Office
3F., Kotani park Bldg., 1-19-25, Edobori, Nishi-ku, Osaka-shi, Osaka, 550-0002 Japan
TEL : [phone] FAX : [phone]
Nagoya Office
4F., Daiei Bldg., 1-11-20, Nishiki, Naka-ku, Nagoya-shi, Aichi, 460-0003 Japan
TEL : [phone] FAX : [phone]
Tsukuba Factory
6127-5, Onogo-machi, Joso-shi, Ibaraki, 300-2521 Japan
TEL : [phone] FAX : [phone]
WORCHEMI TAIWAN CO., LTD. / Taichung, Taiwan
No.915, Zhongshan Rd., Shengang Dist., Taichung City 42955, TAIWAN
TEL : [phone] FAX : [phone]
WORLD CHEMICAL USA, INC. / California, U.S.A.
25691 Atlantic Ocean Dr. Unit B-15 Lake Forest, CA92630
TEL : [phone] FAX : [phone]
SUZHOU WORLD TECHNOLOGY CO., LTD. / Jiangsu, China
402, Fu Yuan Road, Xiang Cheng Economic District, Suzhou, Jiangsu Province, China
TEL : [phone] FAX : [phone]

19
WARNING
DO NOT USE THIS PUMP WITH: SLURRY,
SLUDGE OR OTHER SMALL
PARTICULATES THAT COULD CAUSE
THE PUMP TO BECOME INOPERABLE.
AFTER EACH USE OF THE PUMP, TAKE OUT FROM THE TANK AND
RINSE WELL WITH WATER TO KEEP IT IN OPTIMUM CONDITION.