Bell & Gossett MM 217L User Manual

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Page 1

INSTRUCTION MANUAL

MM-217L

Page 2

Approximate

Distance Above

Cast Line Differential

Setting In. (mm) In. (mm)

Pump Off

/16(24)

/16(8)

Pump On

/8(16)

Burner On

/8(16)

Burner Off

/4(6.4)

Pump Off 13/8(41)

/4(19)

Pump On

/8(16)

Burner On

/8(22)

Burner Off 0 (0)

OPERATION

Maximum Pressure: 150 psi (10.5 kg/cm2)

Settings and Differential Pressures

Values are ± 8” (3.2mm).

Series 150S, 157S

150 psi (10.5 kg/cm

) Levels

150 psi (10.5 kg/cm

) Levels

0 psi

(0 kg/

cm2)

150 psi

(10.5 kg/

cm2)

Approximate

Distance Above

Cast Line Differential

Setting In. (mm) In. (mm)

Pump Off

/16(24)

/8(16)

Pump On

/16(14)

Burner Off 0 (0) N/A

Pump Off 17/16(37)

/4(19)

Pump On

11/16

(17)

Burner Off - 3/8(-16)

N/A

Model 150S-MD, and 157S-MD

0 psi

(0 kg/

cm2)

150 psi

(10.5 kg/

)

Pressure

BURNER OFF

BURNER ON

/8"

DIFFERENTIAL

(22mm)

PUMP

OFF

BURNER

OFF

NORMAL BOILER

WATER LINE

/8"

DIFFERENTIAL

(35mm)

PUMP OFF PUMP ON

/4"

DIFFERENTIAL

(19mm)

PUMP OFF PUMP ON

/4"

DIFFERENTIAL

(19mm)

PUMP

OFF

BURNER

OFF

NORMAL BOILER

WATER LINE

/16"

DIFFERENTIAL

(46mm)

Enclosure rating: NEMA 1 General Purpose

PumpCircuit Rating (Amperes)

Voltage Full Load Locked Rotor Pilot Duty

120 VAC 7.4 44.4

345 VA at

240 VAC 3.7 22.2

120 or 240 VAC

Electrical Ratings

Alarm Circuit Rating

Voltage Amps

120 VAC 1

240 VAC 1/2

Motor Horsepower

Voltage Hp

120 VAC

1/3

240 VAC 1/3

CAUTION:



A more frequent replacement interval may be necessary based on the condition of

•

the unit at time of inspection. McDonnell Miller s warranty is one (1) year from date of installation or two (2) years from the date of manufacture.

Page 3

Approximate

Distance Above

Cast Line Differential

Setting In. (mm) In. (mm)

Motorized

/16(24)

Valve Closed

/16(8)

Motorized

/8(16)

Valve Open

Burner On

/8(16)

Burner Off

/4(6.4)

Motorized 13/8(41)

/4(19)

Valve Closed Motorized

/8(16)

Valve Open

Burner On

/8(22)

Burner Off 0 (0)

Values are ± 8” (3.2mm).

NOTE: Due to the slower operation of some motorized valves, complete valve opening or closing will occur at slightly different levels than indicated above.

Model 158S

150 psi (10.5 kg/cm

) Levels

0 psi

(0 kg/

cm2)

150 psi

(10.5 kg/

)

Pressure

Settings and Differential Pressures (continued)

150 psi

(10.5 kg/

cm2)

Approximate

Distance Above

Cast Line Differential

Setting In. (mm) In. (mm)

Pump Off

/16(24)

/8(16)

Pump On

/16(14)

Burner Off 0 (0) N/A

Pump Off 17/16(37)

/4(19)

Pump On

11/16

(17)

Burner Off -

3/8

(-16)

N/A

Model 158S-MD

0 psi

(0 kg/

cm2)

Pressure

150 psi (10.5 kg/cm2) Levels

NOTE: Due to the slower operation of some motorized valves, complete valve opening or closing will occur at slightly different levels than indicated above.

BURNER OFF

BURNER ON

/8"

DIFFERENTIAL

(22mm)

MOTORIZED

VALV E

CLOSED

BURNER

OFF

NORMAL BOILER

WATER LINE

/8"

DIFFERENTIAL

(35mm)

MOTORIZED

VALV E

CLOSED

MOTORIZED

VALV E

OPEN

/4"

DIFFERENTIAL

(19mm)

MOTORIZED

VALVE

OPEN

CLOSED

/4"

DIFFERENTIAL

(19mm)

MOTORIZED

VALV E

CLOSED

BURNER

OFF

NORMAL BOILER

WATER LINE

/16"

DIFFERENTIAL

(46mm)

Page 4

Values are ± 8” (3.2mm).

150 psi (10.5 kg/cm2) Levels

Approximate

Distance Above

Cast Line Differential

Setting In. (mm) In. (mm)

Pump #1 Off15/16(24)

/16(8)

Pump #1 On5/8(16)

Pump #2 Off5/8(16)

/8(16)

Pump #2 On1/4(6.4)

Pump #1 Off 13/8(41)

/4(19)

Pump #1 On5/8(16)

Pump #2 Off7/8(22)

/8(22)

Pump #2 On

0 (0)

Model 159S

0 psi

(0 kg/

cm2)

150 psi

(10.5 kg/

)

Pressure

Settings and Differential Pressures (continued)

PUMP #1

OFF

PUMP #1

NORMAL BOILER

WATER LINE

(19mm)

/4"

DIFFERENTIAL

PUMP #2 ON AT CAST LINE

/8"

DIFFERENTIAL

(22mm)

PUMP #2

OFF

PUMP #1

OFF

PUMP #2

PUMP #2 ON AT CAST LINE

NORMAL BOILER

WATER LINE

/8"

DIFFERENTIAL

(35mm)

Page 5

a. Using a pipe wrench, unscrew the plastic

float blocking plug (A) from the low water cut-off body (B).

If the control will be the primary low water fuel cut-off, size the steam (top)

and water (bottom) equalizing pipe lengths so that the horizontal cast line on the body is 1a” (35mm) below the boiler’s normal water level, but not lower than the lowest,

safe permissible water level, as determined by the boiler manufacturer.

If the control will be the secondary low water fuel cut-off, size the steam (top) and

water (bottom) equalizing pipe lengths so that the horizontal cast line on the body is

at or above, the lowest, safe permissible water level, as determined by the boiler manufacturer.

STEP 2 - Installing the Low Water Cut-Off

STEP 1 - Determine the Elevation at Which the Low Water Cut-Off/Pump Controller Must be Installed

INSTALLATION

TOOLS NEEDED:

Two (2) pipe wrenches, one (1) flathead screw driver, and pipe sealing compound.

IMPORTANT: Follow the boiler manufacturer's instructions along with all applicable codes and ordinances for piping, blow down valve and water gauge glass requirements.

13/8"

STEAM EQUALIZING PIPE

VERTICAL EQUALIZING PIPE

BLOW DOWN VALVE

NORMAL BOILER WATER LINE

AS A PRIMARY LOW WATER CUT-OFF/PUMP CONTROLLER

BURNER “CUT-OFF LEVEL” AT CAST LINE

LOWEST PERMISSIBLE WATER LEVEL

(35mm)

WATER

EQUALIZING

PIPE

STEAM EQUALIZING PIPE

VERTICAL EQUALIZING PIPE

BLOW DOWN VALVE

AS A SECONDARY LOW WATER CUT-OFF/PUMP CONTROLLER

BURNER “CUT-OFF LEVEL” AT CAST LINE

LOWEST PERMISSIBLE WATER LEVEL

BURNER OFF

WATER

EQUALIZING

PIPE

Series 150S

(except Model 150S-B)

Models 150S-B Series 157S

Page 6

b. Install a water gauge glass (J).

Note: Gauge glass and tri-cocks

not included with product.

a. Install a water column (H) (not

included with product) for all models except Series 157S (with integral water column).

Series 157S

All Other Models

c. Mount and pipe the low water cut-off (D) on

a vertical equalizing pipe (E) at the required elevation level, as determined in Step 1.

Install a full ported blow down valve (G) directly below the lower cross of the water equalizing pipe (F).

Note: 1” NPT tappings are provided, with the exception of some 157 and 157S models which are 14” NPT.

b. For Model 150S-B and Series 157S

(For all other models, proceed to Step 3).

Screw the w” NPT steel plug (C) (provided) in tapping (A).

Series 157S

Models 150S-B

STEP 3 - Installing a Water Gauge Glass

(Required on all steam boilers)

The plug must be reinstalled before control is shipped installed on the boiler, and removed when boiler is installed after shipment. Failure to follow this caution may damage float and operating mechanism.

CAUTION

Page 7

STEP 4 - Electrical Wiring

• To prevent a fire, do not use this product to switch currents over 7.4A, 1/3 Hp at 120 VAC or 3.7A, 1/3 Hp at 240 VAC, unless a starter or relay is used in conjunction with it.

• To prevent electrical shock, turn off the electrical power before making electrical connections.

• This low water cut-off must be installed in series with all other limit and operating controls installed on the boiler. After installation, check for proper operation of all of the limit and operating controls, before leaving the site.

• Modification of the switch assembly before or after installation could cause damage to the boiler and/or boiler system.

Failure to follow this warning could cause electrical shock, an explosion and/or a fire, which could result in property damage, personal injury or death.

WARNING

Switch Operation

For all Models except 158S and 159S

For Model 158S

Boiler feed pump off,

burner on, alarm off.

Boiler feed pump on,

burner on, alarm off.

Boiler feed pump on,

burner off, alarm on.

1 2 4 5 6 1 2 4 5 6

1 2 4 5 6

Motorized valve closed,

burner on, alarm off.

Motorized valve open,

burner on, alarm off.

Motorized valve open,

burner off, alarm on.

4 5 6

1 2

4 5

1 2

4 5

1 2

6 6

For Model 159S

Pump #1 off, pump #2 off.

Pump #1 on,

pump #2 off.

Pump #1 on, pump #2 on.

1 2 5 6 1 2 5 6

1 2 5 6

a. Using a flathead screwdriver, remove the

junction box cover (K).

Page 8

Page 9

WIRING DIAGRAMS

For Motorized Valves, refer to the valve manufacturer's wiring instructions.

Low Water Cut-Off Only

1. Main Line Switch - For burner circuits within the switch’s electrical rating.

1. Main Line Switch - For burner circuits within

the switch’s electrical rating.

2. Pilot Switch - To holding coil of a starter when the burner circuit exceeds the switch’s electrical rating.

LINE LOAD

12 456

ALARM

NEUTRAL

HOT

ALARM

NEUTRAL

HOT

12 456

SEE PUMP

CONTROL

CIRCUIT

TO NEUTRAL

TO BURNER CONTROL CIRCUIT

HOT

ALARM

12 456

LOAD

LINE (3 PHASE)

SEE PUMP

CONTROL

CIRCUIT

ALARM

Combination Pump Control, Low Water Cut-Off and Alarm

Alarm Circuit Only

1. Low Water Alarm 2. High Water Alarm

2. Pilot Switch - To holding coil of a starter when the burner circuit exceeds the switch’s electrical rating.

Pump Control Only

1. Install a starter or relay in pump control circuit, as shown, to prevent damage to snap switch and help insure proper switch/control operation. Failure to do so may shorten the life of the switch when actual amperage exceeds switch rating.

2. Connect wires from holding coil of pump starter or relay to terminals 1 and 2 as shown.

NOTE: To help insure most effective operation, balance boiler feed pump(s) to deliver required water feeder rate to match boiler steaming requirements.

NOTE: For Model 159S, use terminals 5 and 6 from starter or relay for pump # 2.

LINE

12 456

LOAD

LINE

12 456

LOAD

Page 10

STEP 5 - Testing

OFF

a. Turn on the electric power to the boiler. With the

boiler empty the pump should go on and the burner must remain off.

IMPORTANT: Follow the boiler manufacturer’s start-up and operating instructions along with all applicable codes and ordinances. Note: Water levels stated below are only for 150 psi (10.5 kg/cm

) operation.

This control is factory calibrated for specific applications. The following testing procedure is only meant to serve as a verification of proper operating sequence. Dimensions provided are typical for a boiler not being fired and/or not at pressure. Actual operating ranges are shown on page 2 in the "Operation" section.

If the burner comes on, immediately turn the boiler off and make the necessary corrections.

Failure to follow this warning could cause an explosion or fire and result in property damage, personal injury or death.

WARNING

(22mm)

b. The boiler should begin to fill with water.

Watch the gauge glass (J) until the water level reaches approximately d” (22mm) above the horizontal cast line (M) on the low water cut-off.

IMPORTANT: If water does not start filling the boiler, immediately turn off the the boiler and make the necessary corrections.

6. Re-attach the junction box cover (K).

Note:

Cover must be installed correctly as shown

/8"

Page 11

To prevent serious personal injury from steam pipe blow down, connect a pipe to avoid exposure to steam discharge.

Failure to follow this caution could cause personal injury.

CAUTION

INSTALLATION COMPLETE

(22mm)

c. For automatic reset models only. When the water

level reaches approximately d” (22mm) above the horizontal cast line (lower for MD models) the burner should come on (pump #2 should shut off with Model 159S).

For manual reset models only. When the water

level reaches approximately d” (22mm) above the horizontal cast line press the reset button (N). The burner should then come on.

d. Continue watching the gauge glass (J) to

see that the water continues to rise to approximately 1a” (35mm) (1

/16” (37mm)

for MD models) above the horizontal cast line (M). The pump should shut off (the motorized valve should close with Models 158 and 158S, or with Models 159 and 159S, pump #1 should shut off).

Snap Switch Models

Blow down the control when the water in the boiler is at its normal level and the burner is on. Follow Blow Down Procedure found in Maintenance Section on the last page of these instructions.

/8"

Page 12

Xylem Inc.

8200 N. Austin Avenue Morton Grove, Illinois 60053 Phone: (847) 966-3700 Fax: (847) 965-8379 www.mcdonnellmiller.com