SWA-150S Replacement Snap Switch Assembly
Product Information: MM-235G
The MM-235G is a replacement switch assembly model that can be
installed in different models of pressure pumps. The product comes
in four different models, namely SWA-150S, SWA-150S-MD, SWA-158S,
and SWA-159S. The product is designed to operate at a maximum
pressure of 150 psi (10.5 kg/cm2) and has electrical ratings for
voltage, pump circuit rating, and motor horsepower. The product has
different pressure settings and differential pressures for various
models.
Product Usage Instructions
- Verify that you have the correct replacement switch assembly
model before installation. - Refer to the user manual to find the correct replacement switch
model and part number for your specific pump model. - Note that some models with (*) will require head replacement if
manufactured before September 2003 (03J). - Set the pressure setting according to the approximate distance
above cast line differential in (mm) and in (mm) for your specific
model. - Refer to the user manual for the alarm circuit rating, motor
horsepower, and electrical ratings for your specific model. - Note that due to the slower operation of some motorized valves,
complete valve opening or closing will occur at slightly different
levels than indicated in the manual.
INSTRUCTION MANUAL
MM-235G
210369
Verify that you have the Correct Replacement Switch Assembly Model
IMPORTANT: · Installation of an incorrect switch assembly could cause damage to the boiler and/or boiler system. · Modification of the switch assembly before or after installation could cause damage to the boiler
and/or boiler system. · Series 150S and 157S Replacement Snap Switch Assemblies are not interchangeable with Series 150 and 157 mercury
switch controls. · Replacement Switch Assemblies are not interchangeable and must be selected and ordered for the specific control
model in which it will be installed.
For Model
Repl. Switch Model & Part No.
150S 150S-B 150S-M* 150S-B-M* 150S-M-MD* 150S-B-M-MD* 157S 157S-A 157S-P 157S-R 157S-RL 157S-M* 157S-A-M* 157S-R-M* 157S-RB-M* 157S-RL-M* 157S-M-MD* 157S-M-RB-P-MD*
SWA-150S 310462
150S-MD 150S-B-MD 157S-MD 157S-P-MD 157S-R-MD 157S-RB-MD 157S-RB-P-MD 157S-RD-MD 157S-RLS-MD
SWA-150S-MD 310464
158S 158S-M* 158S-M-MD*
159S
SWA-158S 310468
SWA-159S 310470
Model SWA-150S P/N 310462
Model SWA-150S-MD P/N 310464
Model SWA-158S P/N 310468
Model SWA-159S P/N 310470
Manual Reset Models
October 2003 (03K) and Newer
September 2003 (03J) and Older
NOTE: Models with (*) will require head replacement if manufactured before September 2003 (03J)
2
OPERATION
Maximum Pressure: 150 psi (10.5 kg/cm2)
Electrical Ratings
Voltage 120 VAC 240 VAC
Pump Circuit Rating (Amperes)
Full Load Locked Rotor
7.4
44.4
3.7
22.2
Pilot Duty
345 VA at 120 or 240 VAC
Settings and Differential Pressures
Alarm Circuit Rating
Voltage
Amps
120 VAC
1
240 VAC
1/2
Motor Horsepower
Voltage
Hp
120 VAC
1/3
240 VAC
1/3
Series 150S and 157S
Pressure Setting
Approximate Distance Above
Cast Line Differential In. (mm) In. (mm)
0 psi (0 kg/ cm2)
Pump Off Pump On
Burner On Burner Off
15/16 (24) 5/8 (16)
5/8 (16) 1/4 (6.4)
5/16 (8) 3/8 (16)
150 psi (10.5 kg/
cm2)
Pump Off Pump On
Burner On Burner Off
13/8 (41) 5/8 (16)
7/8 (22) 0 (0)
3/4 (19) 7/8 (22)
150 psi (10.5 kg/cm2) Levels
13/8″
DIFFERENTIAL PUMP (35mm) OFF
BURNER OFF
NORMAL BOILER WATER LINE
BURNER “CUT-OFF LEVEL” AT CAST LINE
3/4″
DIFFERENTIAL (19mm)
PUMP OFF PUMP ON
7/8″
DIFFERENTIAL (22mm)
BURNER ON BURNER OFF
BURNER “CUT-OFF LEVEL” AT CAST LINE
Model 150S-MD and 157S-MD
Pressure Setting
Approximate Distance Above
Cast Line Differential In. (mm) In. (mm)
0 psi (0 kg/ cm2)
Pump Off Pump On Burner Off
15/16 (24) 9/16 (14)
0 (0)
3/8 (16) N/A
150 psi Pump Off (10.5 kg/ Pump On
cm2) Burner Off
17/16 (37) 11/16 (17) – 3/8 (-16)
3/4 (19) N/A
150 psi (10.5 kg/cm2) Levels
113/16″
DIFFERENTIAL (46mm)
PUMP OFF
NORMAL BOILER WATER LINE
BURNER OFF
BURNER CUT-OFF LEVEL
3/8″ (9.5mm) BELOW
CAST LINE
3/4″
DIFFERENTIAL (19mm)
PUMP OFF PUMP ON
3
Operation
Settings and Differential Pressures (continued)
Model 158S
Pressure Setting
Approximate Distance Above
Cast Line Differential In. (mm) In. (mm)
0 psi (0 kg/ cm2)
Motorized Valve Closed Motorized Valve Open
15/16 (24) 5/8 (16)
Burner On Burner Off
5/8 (16) 1/4 (6.4)
5/16 (8) 3/8 (16)
Motorized 13/8 (41)
150 psi (10.5 kg/
Valve Closed Motorized
5/8
(16)
cm2) Valve Open
Burner On 7/8 (22)
Burner Off 0 (0)
3/4 (19) 7/8 (22)
150 psi (10.5 kg/cm2) Levels
13/8″
DIFFERENTIAL MOTORIZED (35mm)
VALVE CLOSED
BURNER OFF
NORMAL BOILER WATER LINE
BURNER “CUT-OFF LEVEL” AT CAST LINE
3/4″
DIFFERENTIAL MOTORIZED (19mm)
VALVE CLOSED
MOTORIZED VALVE OPEN
7/8″
DIFFERENTIAL (22mm)
BURNER ON BURNER OFF
BURNER “CUT-OFF LEVEL” AT CAST LINE
NOTE: Due to the slower operation of some motorized valves, complete valve opening or closing will occur at slightly different levels than indicated above.
4
Model 158S-MD
Pressure Setting
0 psi (0 kg/ cm2)
Pump Off Pump On Burner Off
150 psi Pump Off (10.5 kg/ Pump On
cm2) Burner Off
Approximate Distance Above
Cast Line Differential In. (mm) In. (mm)
15/16 (24) 9/16 (14)
3/8 (16)
0 (0)
N/A
17/16 (37) 11/16 (17) – 3/8 (-16)
3/4 (19) N/A
150 psi (10.5 kg/cm2) Levels
113/16″
DIFFERENTIAL (46mm)
MOTORIZED VALVE
CLOSED
BURNER OFF
NORMAL BOILER WATER LINE
BURNER CUT-OFF LEVEL
3/8″ (9.5mm) BELOW
CAST LINE
3/4″
DIFFERENTIAL MOTORIZED (19mm)
VALUE
OPEN CLOSED
NOTE: Due to the slower operation of some motorized valves, complete valve opening or closing will occur at slightly different levels than indicated above.
Settings and Differential Pressures (continued)
Model 159S
Pressure Setting
Approximate Distance Above
Cast Line Differential In. (mm) In. (mm)
0 psi (0 kg/ cm2)
Pump #1 Off 15/16 (24) Pump #1 On 5/8 (16)
Pump #2 Off 5/8 (16) Pump #2 On 1/4 (6.4)
5/16 (8) 3/8 (16)
Pump #1 Off 13/8 (41)
150 psi (10.5 kg/
Pump #1 On
5/8
(16)
cm2) Pump #2 Off 7/8 (22)
Pump #2 On 0 (0)
3/4 (19) 7/8 (22)
150 psi (10.5 kg/cm2) Levels
13/8″
DIFFERENTIAL (35mm)
PUMP #1 OFF
PUMP #2 ON
NORMAL BOILER WATER LINE
PUMP #2 ON AT CAST LINE
3/4″
DIFFERENTIAL (19mm)
PUMP #1 OFF
PUMP #1 ON
7/8″
DIFFERENTIAL (22mm)
PUMP #2 OFF
PUMP #2 ON
PUMP #2 ON AT CAST LINE
Switch Level Ruler
Cut to actual size and attach to piece of cardboard.
TOP 3″
(76.2mm)
CUT HERE
2″ (50.8mm)
1″ (25.4mm)
Casting Cut-Off Line
1″ (25.4mm)
5
INSTALLATION
SECTION 1 – Switch Bracket Replacement
! WARNING
· 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. 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.
1. Turn the boiler off. ON
2. Allow the boiler to cool to 80°F (27°C) and release the boiler pressure to 0 psi (0 bar). Drain water in the boiler to a level which is below the float chamber (A).
OFF A
3. Remove the cover (B).
B
4. Mark and remove the pump switch and burner/alarm switch wires from terminal block.
Terminal Connection Reference Chart
Product 150S/157S
158S
159S
Switch
2 Wire Pump
3 Wire Burner
3 Wire Pump
3 Wire Burner
2 Wire Pump
2 Wire Burner
1 Blue
Black
Blue
2 Yellow
White
Yellow
Terminal Connection
3
4
5
6
Black White Red Red
Black White Red
Blue Yellow
PUMP CIRCUIT TERMINALS
ALARM CIRCUIT TERMINALS
LOW WATER CUT-OFF
TERMINALS
PUMP SWITCH
LOW WATER CUT-OFF AND ALARM SWITCH
6
SECTION 1 – Switch Bracket Replacement (continued)
5a. Locate the actuator assembly (C) and the two fillister head
C
screws (D) which secure it to the bearing of the control.
b. Clean the inspection lacquer out of the screw slots in the two fillister head screws.
c. Remove the two screws holding the actuator assembly in place using a flat head screwdriver. Remove actuator assembly and place aside for reinstallation.
6a. Remove the two Torx® screws (E) holding the switch bracket assembly in place using a flat head screwdriver or a Torx® T30 wrench.
b. Take the new switch bracket assembly out of the package and place the bagged supplies to one side while discarding the insert. NOTE: Refer to the chart on page 2 to make sure you have the proper switch bracket assembly for your control. The switch bracket assemblies are not interchangeable.
c. Install the new switch bracket assembly (F) into the junction box in the same orientation as the old switch bracket assembly (i.e. with arrows on the bracket pointing toward the terminal block).
d. Secure the new assembly with Torx® screws (E) and torque to 80 – 140 in. lb. (92 – 161 cm. kg.).
D
E F
7a. Reattach the actuator assembly using the two fillister head screws (G) and torque to 30 – 40 in. lb. (34.5 – 46 cm. kg.).
G
b. Apply a drop of the supplied adhesive to the threads of each fillister head screw.
8. Reconnect the pump switch and burner/ alarm switch wires to terminal block as noted when disconnected and torque to 13 – 17 in. lb. ( 15 – 19.5 cm. kg.) (Refer to “Terminal Connection Chart” on page 6 if unsure of proper switch to terminal block wire connections).
9. Reattach the cover (H).
H
Note: Cover must be installed correctly as shown
Proceed with normal operational checks of controls as described in Step 2 “Checking Switch Settings and Adjusting Switch Setpoints at Operating Pressure”; or Section 3 “Checking Switch Settings at “0” Pressure”.
The pump or burner switch operating points should be within +/- 1/8″ of those specified for your control.
7
INSTALLATION
SECTION 2 – Checking Switch Settings and Adjusting Switch Setpoints at Operating Pressure
IMPORTANT: All switches have fixed differentials. Adjustment of switches referred to in Step 2 and 3 are all based upon Pump Off and Burner Off setpoints. The Pump On and Burner On setpoints are not adjustable.
We strongly recommend that you check the control at both the operating pressure and at 0 pressure. All boilers start at 0 psi regardless of the operating pressure. The operating points will spread out as the pressure goes up and shrink as the pressure goes down.
1. Cut out the “Switching Level Ruler” (page 5) along the indicated lines.
3″ (76.2mm)
2″ (50.8mm)
1″ (25.4mm) Casting Cut-Off Line
(Not to Scale. Template located on page 5).
1″ (25.4mm)
2a. Hold the ruler against the side of the gauge glass in a position so the “Cast Line” mark is on the same level as the Cast Line on the float chamber of the control (I) (a carpenter’s level should be used to insure the cast line on the float chamber is at the same level as the one on the ruler).
b. Once the ruler is properly positioned, tape it to the gauge glass.
RULER
LEVEL I
3a. Bring boiler up to normal operating pressure and turn the
pump off.
J
b. Remove the cover (J).
8
4 – Setting the Operating Points of the Burner Switch
IMPORTANT: Where Pump On/Off and Burner On/Off are referenced in these instructions, Pump #1 On/Off and Pump #2 Off/On should be substituted, respectively, for a 159S control, and Motorized Valve Open/Closed can substitute for Pump On/Off for a 158S control.
4a. Slowly bring the boiler water level down to the point at which the burner cuts off. If the burner does not shut off automatically by the time the water level reaches 3/8″ (9.5mm) below the cast line on the unit body, shut the burner off manually.
BURNER ON BURNER OFF
BURNER “CUT-OFF LEVEL” AT CAST LINE
4b. If the cut-off point does not match the one as shown in chart for the control (pages 3, 4, or 5) as measured on the “Switch Level Ruler” dig the inspection lacquer out of the socket in the set screw (K) above the burner switch in the actuator assembly using an awl.
c. Using an Allen wrench with a 5/64″ hex, turn the screw 1/4 turn: – clockwise (if the “Burner Off” point is too high when viewed from top) – counterclockwise (if the “Burner Off” point is too low when viewed from top) – for manual reset units with date codes of 03K and newer, the set screw should be turned opposite the above direction to obtain desired results.
4d. Turn the pump back on, allowing the boiler to fill with water.
e. Reset the burner switch (L) for manual
L
reset models once the pump shuts off.
NOTE
Manual reset units with date codes of 03K and newer require the cover to be installed for proper operation of the manual reset mechanism.
K
BURNER SET SCREW
BURNER SWITCH
4f. Repeat steps a. through d. as necessary to match the Burner Off point specification for your model.
g. Apply one drop of adhesive (furnished) to the set screw threads (M) above the burner switch in the actuator assembly.
M ADD ADHESIVE HERE 9
COMMERCIAL WARRANTY Warranty. For goods sold to commercial buyers, Seller warrants the goods sold to Buyer hereunder (with the exception of membranes, seals, gaskets, elastomer materials, coatings and other “wear parts” or consumables all of which are not warranted except as otherwise provided in the quotation or sales form) will be (i) be built in accordance with the specifications referred to in the quotation or sales form, if such specifications are expressly made a part of this Agreement, and (ii) free from defects in material and workmanship for a period of one (1) year from the date of installation or two (2) years from the date of manufacture, whichever shall occur first, unless a longer period is specified in the product documentation (the “Warranty”). Except as otherwise required by law, Seller shall, at its option and at no cost to Buyer, either repair or replace any product which fails to conform with the Warranty provided Buyer gives written notice to Seller of any defects in material or workmanship within ten (10) days of the date when any defects or non-conformance are first manifest. Under either repair or replacement option, Seller shall not be obligated to remove or pay for the removal of the defective product or install or pay for the installation of the replaced or repaired product and Buyer shall be responsible for all other costs, including, but not limited to, service costs, shipping fees and expenses. Seller shall have sole discretion as to the method or means of repair or replacement. Buyer’s failure to comply with Seller’s repair or replacement directions shall terminate Seller’s obligations under this Warranty and render the Warranty void. Any parts repaired or replaced under the Warranty are warranted only for the balance of the warranty period on the parts that were repaired or replaced. Seller shall have no warranty obligations to Buyer with respect to any product or parts of a product that have been: (a) repaired by third parties other than Seller or without Seller’s written approval; (b) subject to misuse, misapplication, neglect, alteration, accident, or physical damage; (c) used in a manner contrary to Seller’s instructions for installation, operation and maintenance; (d) damaged from ordinary wear and tear, corrosion, or chemical attack; (e) damaged due to abnormal conditions, vibration, failure to properly prime, or operation without flow; (f) damaged due to a defective power supply or improper electrical protection; or (g) damaged resulting from the use of accessory equipment not sold or approved by Seller. In any case of products not manufactured by Seller, there is no warranty from Seller; however, Seller will extend to Buyer any warranty received from Seller’s supplier of such products. THE FOREGOING WARRANTY IS EXCLUSIVE AND IN LIEU OF ANY AND ALL OTHER EXPRESS OR IMPLIED WARRANTIES, GUARANTEES, CONDITIONS OR TERMS OF WHATEVER NATURE RELATING TO THE GOODS PROVIDED HEREUNDER, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, WHICH ARE HEREBY EXPRESSLY DISCLAIMED AND EXCLUDED. EXCEPT AS OTHERWISE REQUIRED BY LAW, BUYER’S EXCLUSIVE REMEDY AND SELLER’S AGGREGATE LIABILITY FOR BREACH OF ANY OF THE FOREGOING WARRANTIES ARE LIMITED TO REPAIRING OR REPLACING THE PRODUCT AND SHALL IN ALL CASES BE LIMITED TO THE AMOUNT PAID BY THE BUYER FOR THE DEFECTIVE PRODUCT. IN NO EVENT SHALL SELLER BE LIABLE FOR ANY OTHER FORM OF DAMAGES, WHETHER DIRECT, INDIRECT, LIQUIDATED, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY OR SPECIAL DAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF PROFIT, LOSS OF ANTICIPATED SAVINGS OR REVENUE, LOSS OF INCOME, LOSS OF BUSINESS, LOSS OF PRODUCTION, LOSS OF OPPORTUNITY OR LOSS OF REPUTATION. LIMITED CONSUMER WARRANTY Warranty. For goods sold for personal, family or household purposes, Seller warrants the goods purchased hereunder (with the exception of membranes, seals, gaskets, elastomer materials, coatings and other “wear parts” or consumables all of which are not warranted except as otherwise provided in the quotation or sales form) will be free from defects in material and workmanship for a period of one (1) year from the date of installation or two (2) years from the product date code, whichever shall occur first, unless a longer period is provided by law or is specified in the product documentation (the “Warranty”). Except as otherwise required by law, Seller shall, at its option and at no cost to Buyer, either repair or replace any product which fails to conform with the Warranty provided Buyer gives written notice to Seller of any defects in material or workmanship within ten (10) days of the date when any defects or non-conformance are first manifest. Under either repair or replacement option, Seller shall not be obligated to remove or pay for the removal of the defective product or install or pay for the installation of the replaced or repaired product and Buyer shall be responsible for all other costs, including, but not limited to, service costs, shipping fees and expenses. Seller shall have sole discretion as to the method or means of repair or replacement. Buyer’s failure to comply with Seller’s repair or replacement directions shall terminate Seller’s obligations under this Warranty and render this Warranty void. Any parts repaired or replaced under the Warranty are warranted only for the balance of the warranty period on the parts that were repaired or replaced. The Warranty is conditioned on Buyer giving written notice to Seller of any defects in material or workmanship of warranted goods within ten (10) days of the date when any defects are first manifest. Seller shall have no warranty obligations to Buyer with respect to any product or parts of a product that have been: (a) repaired by third parties other than Seller or without Seller’s written approval; (b) subject to misuse, misapplication, neglect, alteration, accident, or physical damage; (c) used in a manner contrary to Seller’s instructions for installation, operation and maintenance; (d) damaged from ordinary wear and tear, corrosion, or chemical attack; (e) damaged due to abnormal conditions, vibration, failure to properly prime, or operation without flow; (f) damaged due to a defective power supply or improper electrical protection; or (g) damaged resulting from the use of accessory equipment not sold or approved by Seller. In any case of products not manufactured by Seller, there is no warranty from Seller; however, Seller will extend to Buyer any warranty received from Seller’s supplier of such products. THE FOREGOING WARRANTY IS PROVIDED IN PLACE OF ALL OTHER EXPRESS WARRANTIES. ALL IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED TO ONE (1) YEAR FROM THE DATE OF INSTALLATION OR TWO (2) YEARS FROM THE PRODUCT DATE CODE, WHICHEVER SHALL OCCUR FIRST. EXCEPT AS OTHERWISE REQUIRED BY LAW, BUYER’S EXCLUSIVE REMEDY AND SELLER’S AGGREGATE LIABILITY FOR BREACH OF ANY OF THE FOREGOING WARRANTIES ARE LIMITED TO REPAIRING OR REPLACING THE PRODUCT AND SHALL IN ALL CASES BE LIMITED TO THE AMOUNT PAID BY THE BUYER FOR THE DEFECTIVE PRODUCT. IN NO EVENT SHALL SELLER BE LIABLE FOR ANY OTHER FORM OF DAMAGES, WHETHER DIRECT, INDIRECT, LIQUIDATED, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY OR SPECIAL DAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF PROFIT, LOSS OF ANTICIPATED SAVINGS OR REVENUE, LOSS OF INCOME, LOSS OF BUSINESS, LOSS OF PRODUCTION, LOSS OF OPPORTUNITY OR LOSS OF REPUTATION. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you. Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above exclusions may not apply to you. This warranty gives you specific legal rights, and you may also have other rights which may vary from state to state. To make a warranty claim, check first with the dealer from whom you purchased the product or call +1-847-966-3700 for the name and location of the nearest dealer providing warranty service.
Xylem Inc. 8200 N. Austin Avenue Morton Grove, Illinois 60053 Phone: (847) 966-3700 Fax: (847) 965-8379 www.mcdonnellmiller.com
McDonnell & Miller is a trademark of Xylem Inc. or one of its subsidiaries. © 2015 Xylem Inc. MM-235G October 2015 Part No. 210369
McDonnell & Miller | Xylem US
