background image

4

Two groove sheaves are supplied with 
both grooves set at the same pitch diam-

eter. Both movable flanges must be rotated 

the same number or turns to ensure the 
same pitch diameter for satisfactory op-
eration. 

Do not open sheaves more than five turns 

for “a” belt or 6 turns for “b” belt. Doing 
so may cause the belts to sit improperly, 

and cause the flanges to detach in service. 

6.  Replace key (D).

7.  Tighten setscrew (B) in outer locking ring and 

capscrew (C) with torque wrench to the values in 

 

Table 1 on page 22

 .

8.  Put on belts and adjust belt tension properly. 

Refer 

to Belt Section for tensioning instructions.

9.  Be sure that all keys are in place. Be sure that all 

setscrews and capscrews are torqued properly be-
fore starting drive. Check setscrews and belt ten-
sion after 24 hours of service.

Belts

Adjusting Belt Tension.

See 

Figure 14 on page 27

LD14011

DEFLECTION FORCE

D

C

d

SPAN LENG

TH

FIGURE 14 - 

BELT TENSION

1.  Measuring belt span. Lay a tape measure along 

the top of the belt, measure between the points at 
which the outside of the belt meets the outside of 
the sheaves. The following formula can be used to 
calculate the belt span.

LD14003

2

2

2

 −

=

d

D

C

Span

C = Center distance shaft to shaft

D = Driver sheave (large sheave) pitch diameter

d  = Driver sheave (small sheave) pitch diameter

2. 

Calculate deflection (Deflection = Span ÷ 64)

3.  See 

Table 6 on page 28 

for  correct  deflection 

force.

4.  Using a spring scale, apply force at right angle to 

the midpoint of the belt span (see 

Figure 14 on 

page 27

).

5. 

Check  the  tension  at  least twice during  the  first 

day of operation, and periodically there after.

How to Increase Belt Life 

•  Keep sheaves and belts clean. Abrasive dust, rust, 

oils, and acids reduce service life.

•  Give drives clearance. Never let belts run against 

belt guards or other obstructions.

•  Never force belts. Move motor on adjustment 

base so belts go on easily.

•  Eliminate slack. Adjust motor and tighten belts 

in position. Slack belts wear excessively which 
cause slippage and deliver less air.

•  Use matched belts. Matched belts run smoother 

and last longer because the load is evenly distrib-
uted. Never partially replace a set of belts.

•  Mount belts straight. Shaft must be parallel and 

sheave grooves in alignment to prevent unneces-
sary belt wear.

• 

Do not overload belt. Belts have a specific HP rat

-

ing that must not be exceeded.

ENVIRO-TEC

27

SECTION 4 - PERIODIC MAINTENANCE AND SERVICE

FORM ET102.19-NOM1 (0521)

Содержание MQL B Series

Страница 1: ...MODEL MQL SERIES B INSTALLATION OPERATION MAINTENANCE INDOOR AIR HANDLING UNIT Supersedes ET102 19 NOM1 517 Form ET102 19 NOM1 0521...

Страница 2: ...r with and comply with all applicable governmental standards and regulations pertaining to the task in question SAFETY SYMBOLS The following symbols are used in this document to alert the reader to sp...

Страница 3: ...ushing or dismember ment injuries HOT PARTS HAZARDS Electric Resis tance heating elements must be discon nected prior to servicing Electric Heaters may start automatically disconnect all power and con...

Страница 4: ...y rigging and lifting equipment All assemblies must be adequately se cured during lifting and rigging by temporary supports and restraints until equipment is permanently fastened and set in its final...

Страница 5: ...rnal Isolation 15 External Isolation 15 Service Clearance 15 Panel Removal 15 General Piping 15 DX Connection Steps 16 In the field 16 Notes 16 Condensate Drain 16 Electrical Installation 16 INSPECTIO...

Страница 6: ...25 Mounting Straight Bore Sheaves 25 Mounting Split Tapper Sheaves 26 Adjust Variable Pitched Sheaves 26 Belts 27 Adjusting Belt Tension 27 How to Increase Belt Life 27 Coils 28 Steam Hot Water and Ch...

Страница 7: ...Sheaves 21 FIGURE 12 Sheave Alignment 22 FIGURE 13 Split Tapper Sheave Mounting 22 FIGURE 14 Belt Tension 23 TABLE 1 Minimum Hex Head Bolt Torque In Lb Ft Grade 5 Bolt 18 TABLE 2 Recommended Greasing...

Страница 8: ...THIS PAGE INTENTIONALLY LEFT BLANK ENVIRO TEC 8 FORM ET102 19 NOM1 0521 LIST OF FIGURES...

Страница 9: ...To ensure the assembled MQL modules are in the proper sequence each module has an identifying code and an airflow direction label The proper assembly sequence is listed on the supply fan nametag The...

Страница 10: ...balanced Rough handling may cause bearing misalignment and or shaft damage STORAGE To transfer equipment from truck to storage site refer to Rigging And Handling on page 9 If a forklift is used lift...

Страница 11: ...e actuator if the damp ers are the same size If the dampers are different sizes they must be driven by individual actuators and con trolled separately b Remove all shipped loose parts from job site to...

Страница 12: ...THIS PAGE INTENTIONALLY LEFT BLANK ENVIRO TEC 12 FORM ET102 19 NOM1 0521 Section 1 introduction...

Страница 13: ...ed from a ceil ing a base rail angle iron or channel must support the equipment The MQL product line is not designed to be suspended from the top of the equipment Be fore hanging the equipment all fie...

Страница 14: ...Left Hand Fan Access Door Figure 7 HAND IDENTIFICATION ENVIRO TEC 14 FORM ET102 19 NOM1 0521 Section 2 installation...

Страница 15: ...oil module is also isolated the piping must be isolated or have a flexible connection to prevent coil header damage due to equipment movement All piping wiring ductwork and external connections must b...

Страница 16: ...at pump condensing units but require the addition of fittings or refrigerant specialties to be furnished and installed by others Condensate Drain All condensate drains must have a trap installed This...

Страница 17: ...l Outside Air For Freeze Protection Proper Supply Return Grille Type Size Used Insulate All Ductwork As Required Verify All Ductwork Is Complete Dampers And Filters Are Installed Prior To Startup E EL...

Страница 18: ...INTENTIONALLY LEFT BLANK ENVIRO TEC 18 FORM ET102 19 NOM1 0521 Section 2 installation...

Страница 19: ...nly qualified individuals should perform these tasks Before entering the fan section make sure that the fan electrical power source is disconnected locked and tagged out in the OFF position 1 Check th...

Страница 20: ...pment 7 Manually rotate motor shaft to ensure that it ro tates freely 8 Replace all panels that were removed during in stallation 9 Momentarily apply power and check direction of rotation of motor sha...

Страница 21: ...sheaves Tighten sheave set screws to the proper torque see Table 1 on page 22 Check and adjust fan belt tension Tighten electrical connections Inspect coils for dirt build up or coil freeze up Every...

Страница 22: ...posal of their product 6 Immediately rinse the drain pan thoroughly with fresh water to prevent potential corrosion from the cleaning solution of the drain pan and drain line components 7 Allow the un...

Страница 23: ...ch conforms to NLGI Number 2 for consis tency See Table 2 on page 23 Table 3 on page 23 and Table 4 on page 23 for recommended greasing intervals operating range and bearing grease capacities Table 2...

Страница 24: ...of operation It is important to remember that this recommendation is base of average use Refer to Table 2 on page 23 for additional information Types of Grease A high grade ball or roller bearing grea...

Страница 25: ...5 The sheave should be close to the motor as possible with setscrew A in full contact with the key If the setscrew a is not fully in contact with key the sheave assembly could come off 4 Be sure that...

Страница 26: ...ft 8 Tighten capscrews progressively with wrench Dothis following a star pattern taking a partial turn on each capscrew successively until all are tight see Table 1 on page 22 for proper torque Do not...

Страница 27: ...be used to calculate the belt span LD14003 2 2 2 d D C Span C Center distance shaft to shaft D Driver sheave large sheave pitch diameter d Driver sheave small sheave pitch diameter 2 Calculate deflect...

Страница 28: ...urface of the coil reduces its ability to transfer heat that can result in reduced performance and increased operating energy costs If the dirt on the surface of the coil becomes wet which commonly oc...

Страница 29: ...10 Use caution to assure that any contaminated ma terial does not contact other areas of the unit or building Properly dispose of all contaminated ma terials and cleaning solutions Winterizing Water C...

Страница 30: ...ON LEVELS FAN SPEED RPM VIBRATION 800 or less 5 mils maximum displacement 801 or greater 20 in sec Maximum velocity Note Excessive vibration from any cause contributes to premature fan and motor beari...

Страница 31: ...l applications to prevent retaining con densate in the coil Generally the vacuum breaker is to be connected between the coil inlet and the return main the vacuum breaker should be open to the atmosphe...

Страница 32: ...se fresh air dampers if steam supply pressure falls below minimum specified Water Heating Coils 1 Water supply and water return connections extend through the end panel of the coil section All con nec...

Страница 33: ...k bear ing lubricant MOTOR STALLS Open phase Check line for an open phase Overloaded motor Reduce load or replace with larger motor Low line voltage Check voltage across AC line Correct voltage if pos...

Страница 34: ...ignment Loosen bearing setscrews and realign see Fig 10 Inadequate lubrication Grease bearing s LOW COIL CAPACITY CHILLED WATER Air is bypassing coil Prevent bypass with block offs Coil tubes are bloc...

Страница 35: ...5 ENVIRO TEC 35 Section 5 TROUBLESHOOTING FORM ET102 19 NOM1 0521...

Страница 36: ...Catalog ET102 19 NOM1 0521 Supersedes ET102 19 NOM1 517 ENVIRO TEC is a mark and or registered mark Unauthorized use is strictly prohibited 2021 Johnson Controls www enviro tec com...

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