Install Instructions

ManualsBrandsMcdonnell & Miller ManualsHeating Supplies157S-RL-M, Float Type, Combo LWCO & Pump Controller w/ Water Column, w/ Alternate Tappings and Manual Reset

INSTRUCTION MANUAL

MM-217J

• Before using this product read and understand instructions.

• Save these instructions for future reference.

• All work must be performed by qualified personnel trained in the proper application, instal-

lation, and maintenance of plumbing, steam, and electrical equipment and/or systems in

accordance with all applicable codes and ordinances.

• To prevent serious burns, the boiler must be cooled to 80˚F (27˚C) and the pressure must be

0 psi (0 bar) before servicing.

• 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.

• We recommend that secondary (redundant) Low Water Cut-Off controls be installed on all

steam boilers with heat input greater than 400,000 BTU/hour or operating above 15 psi of

steam pressure. At least two controls should be connected in series with the burner control

circuit to provide safety redundancy protection should the boiler experience a low water

condition. Moreover, at each annual outage, the low water cut-offs should be dismantled,

inspected, cleaned, and checked for proper calibration and performance.

•

To prevent serious personal injury from steam blow down, connect a drain pipe to the control

opening to avoid exposure to steam discharge.

• To prevent a fire, do not use this low water cut-off 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.

Failure to follow this warning could cause property damage, personal injury or death.

NING

UTIO

WARNING

Series 150S and 157S

(Snap Switch, All Models except 157S-RB-P)

Low Water Cut-Off/Pump Controllers

For Steam Boilers and Other Level Control Applications

Typical Applications:

– Primary or secondary pump controller/

low water fuel cut-off

for steam boilers

– Motorized valve controller

– Low water cut-off

– High water cut-off

– Alarm actuator

Series 157S

Series 150S

Summary of content (12 pages)

PAGE 1
INSTRUCTION MANUAL MM-217J Series 150S and 157S (Snap Switch, All Models except 157S-RB-P) Low Water Cut-Off/Pump Controllers For Steam Boilers and Other Level Control Applications Series 150S Typical Applications: – Primary or secondary pump controller/ low water fuel cut-off for steam boilers – Motorized valve controller – Low water cut-off – High water cut-off – Alarm actuator Series 157S ! WARNING ION CAUT ING WARN • • Before using this product read and understand instructions.
PAGE 2
OPERATION Maximum Pressure: 150 psi (10.5 kg/cm2) Electrical Ratings PumpCircuit Rating (Amperes) Full Load Locked Rotor 7.4 44.4 3.7 22.2 Voltage 120 VAC 240 VAC Pilot Duty 345 VA at 120 or 240 VAC Alarm Circuit Rating Voltage Amps Motor Horsepower Voltage Hp 120 VAC 1 120 VAC 1/3 240 VAC 1/2 240 VAC 1/3 Enclosure rating: NEMA 1 General Purpose Settings and Differential Pressures Values are ± 8” (3.2mm).
PAGE 3
Settings and Differential Pressures (continued) Values are ± 8” (3.2mm). Model 158S Pressure 0 psi (0 kg/ cm2) Model 158S-MD Approximate Distance Above Cast Line Differential In. (mm) In. (mm) Setting Motorized Valve Closed Motorized Valve Open 15/16 5/8 (16) Burner On Burner Off 5/8 (16) (6.4) 1/4 Motorized 13/8 Valve Closed 150 psi 5/8 (10.5 kg/ Motorized Valve Open cm2) 7/8 Burner On Burner Off 0 150 psi (10.
PAGE 4
Settings and Differential Pressures (continued) Values are ± 8” (3.2mm). Model 159S Setting Pressure 0 psi (0 kg/ cm2) Approximate Distance Above Cast Line Differential In. (mm) In. (mm) Pump #1 Off Pump #1 On 15/16 Pump #2 Off Pump #2 On 5/8 5/8 1/4 (24) (16) 5/16 (8) (16) (6.4) 3/8 (16) 3/4 (19) 7/8 (22) Pump #1 Off 13/8 (41) 5/8 (16) 150 psi Pump #1 On (10.5 kg/ Pump #2 Off cm2) Pump #2 On 7/8 (22) (0) 0 150 psi (10.
PAGE 5
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.
PAGE 6
Models 150S-B b. For Model 150S-B and Series 157S (For all other models, proceed to Step 3). C Series 157S C A Screw the w” NPT steel plug (C) (provided) in tapping (A). A ! CAUTION 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. c.
PAGE 7
STEP 4 - Electrical Wiring ! WARNING • 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.
PAGE 8
b. Following the appropriate wiring diagram, (refer to page 9) based on your application requirements, and using BX armored cable or Thinwall electrical metal tubing connector fittings, make electrical connections to the junction box (L). IMPORTANT: There must be a minimum space of 1/2” (13mm) between connector fittings and electrical live metal parts.
PAGE 9
WIRING DIAGRAMS For Motorized Valves, refer to the valve manufacturer's wiring instructions. Low Water Cut-Off Only 2. Pilot Switch - To holding coil of a starter when the burner circuit exceeds the switch’s electrical rating. 1. Main Line Switch - For burner circuits within the switch’s electrical rating. LINE LINE LOAD 1 2 OR 4 5 6 1 2 4 5 6 LOAD Pump Control Only NOTE: For Model 159S, use terminals 5 and 6 from starter or relay for pump # 2. 1.
PAGE 10
6. Re-attach the junction box cover (K). K Note: Cover must be installed correctly as shown STEP 5 - Testing 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.
PAGE 11
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). Snap Switch Models N OR 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.
PAGE 12
MAINTENANCE BLOW DOWN PROCEDURE: SCHEDULE: ! Blow down control as follows when boiler is in operation. • Daily if operating pressure is above 15 psi. • Weekly if operating pressure is below 15 psi. NOTE More frequent blow-down may be necessary due to dirty boiler water and/or local codes. • Remove head assembly and inspect water side components annually. Replace head assembly if any of the internal components are worn, corroded or damaged or if control no longer operates properly.