Xylem MM 414B User Manual

Series 150E and 157E
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 and high water cut-off – Dual pump control – Alarm actuator
A
B
• 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, instal­lation, 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 16A, 1 Hp at 120 VAC or 8A, 1 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.
WARNING
CAUTION
!
WARNING
Series 150E
Series 157E
®
with
MERCURY FREE
1 HP Relays
U.S. Pat. No. 6,571,625
McDonnell & Miller
Installation & Maintenance
Instructions
MM-414(B)
SPECIFICATIONS
Maximum Pressure: 150 psi (10.5 kg/cm2)
2
FEATURES
Burner Delay (DOB): 0 to 60 seconds (Field Adjustable)
Ambient Temp: 120˚F Max.
NOTE: The circuit board is protected with a sensor which will shut down the unit if the temperature at the board exceeds 176˚F (80˚C). The board will reset when the temperature at the board drops below 167˚F (75˚C).
Burner Relay Time Delay
There is a field-adjustable time delay (DOB) to prevent nuisance burner shut-down. The number of seconds water needs to be off the bottom probe before the burner relay is deactivated can be set between 0 and 60 seconds.
Redundant Low Water Cut-Off
When the boiler water drops below the middle probe, a 3 minute timing circuit will be activated. If water does not return to the middle probe within three minutes, the burner relay will deactivate. The Red LED will flash once every second if this condition occurs.
•Automatic Reset units will automatically reset when the water level is restored to the middle probe.
• The reset button on Manual Reset units will have to be pressed after water is restored to the middle probe.
NOTE: The timing circuit will automatically reset if the water level is restored to the middle probe within 3 minutes.
Redundant Pump Off
The pump relay will be activated after water drops below the middle probe. If the water level is not restored to the top probe within 3 minutes the pump relay will be deactivated. After the pump relay is deactivated, normal operation is resumed. Water must again drop off the middle probe to activate the pump relay. There is no LED signal for this occurance.
CSD-1 Code Compliance
On Manual Reset units, if the control is in a low water condition (burner relay deactivated) prior to an interruption of power, the control will remain in a low water condition when power is restored. The reset button will need to be pressed when the water level again covers the middle probe.
Adjustable Pump Differentials
ELECTRICAL RATINGS & SWITCH RATINGS
Supply Probe Full Load (Amps) Locked Rotor (Amps) Pilot Duty (VA) Motor (HP) Voltage Voltage NO (NC), VAC NO (NC), VAC NO (NC), VAC NO (NC), VAC
120 VAC 5 VAC 16 (5.8), 120 96 (34.8), 120 470 (290), 120 1 (1/4), 120 50/60 HZ maximum 8 (2.9), 240 48 (17.4), 240 470 (290), 240 1 (1/4), 240
3
BURNER
CUT-OFF LEVEL
AT CAST LINE
(22mm)
BURNER OFF
BURNER ON
7
/8"
PUMP
OFF
BURNER
OFF
BURNER
CUT-OFF LEVEL
AT CAST LINE
2
1
/16"
(52 mm)
NORMAL BOILER
WATER LINE
1
3
/16"
(30 mm)
PUMP OFF
PUMP ON
NORMAL BOILER
WATER LINE
When the water level in the boiler drops below the middle probe, the circuit is broken which will acti­vate the pump relay. When the water level rises above the top probe, the circuit is made and the pump relay is deactivated.
The distance between the top and middle probes is adjustable. By turning the flange one bolt hole clockwise, the distance can be increased by 7/16”.
When the water level in the boiler drops below the bottom probe, the circuit is broken which will deacti­vate the burner relay. When the water level is restored to the middle probe, the burner relay will be activated for auto reset controls only.
SWITCH SETTINGS:
Values are ±
3
/16” (6mm).
Flange in “B” PositionFlange in “A” Position
Burner Off has adjustable 0-60 second time delay.
Approximate
Distance Above
Cast Line Differential
Setting In. (mm) In. (mm)
Pump Off 1
5
/8 (41)
3
/4 (19)
Pump On
7
/8 (22)
Burner On
7
/8 (22)
7
/8 (22)
Burner Off 0 (0)
BURNER
CUT-OFF LEVEL
AT CAST LINE
(22mm)
BURNER OFF
BURNER ON
7
/8"
PUMP
OFF
BURNER
OFF
BURNER
CUT-OFF LEVEL
AT CAST LINE
1
5
/8"
(41mm)
NORMAL BOILER
WATER LINE
3
/4" (19 mm)
PUMP OFF
PUMP ON
NORMAL BOILER
WATER LINE
Burner Off has adjustable 0-60 second time delay.
Approximate
Distance Above
Cast Line Differential
Setting In. (mm) In. (mm)
Pump Off 2
1
/16 (52)
13/16(30)
Pump On
7
/8 (22)
Burner On
7
/8 (22)
7
/8(22)
Burner Off 0 (0)
4
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 1
3
/8” (35mm) below the boiler’s normal water level, but not lower than the lowest safe permissible water level, as determined by the boiler manufacturer.
OR
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 1 - Determine the Elevation at Which the Low Water Cut-Off/Pump Controller Must be Installed
INSTALLATION –
TOOLS NEEDED:
Tw o (2) pipe wrenches, one (1) flatblade screw­driver, 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
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
BLOW DOWN VALVE
BLOW DOWN VALVE
STEAM EQUALIZING PIPE
VERTICAL EQUALIZING PIPE
BLOW DOWN VALVE
BURNER CUT-OFF LEVEL AT CAST LINE
LOWEST PERMISSIBLE WATER LEVEL
BURNER OFF
WATER
EQUALIZING
PIPE
AS A SECONDARY LOW WATER CUT-OFF/PUMP CONTROLLER
BLOW DOWN VALVE
b. Install a water gauge glass (J).
Note: Gauge glass and tri-cocks
not included with product.
J
5
F
E
D
a. 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 blow down valves directly below the lower cross of the water equalizing pipe (F).
STEP 2 - Installing the Low Water Cut-Off
J
H
a. Install a water column (H) (not included with
product) for all models except Series 157E, (with integral water column).
STEP 3 - Installing a Water Gauge Glass (Required on all steam boilers)
Series 157E
All Other Models
GAUGE GLASS
(TYPICAL)
TRI-COCK (TYPICAL)
6
Cover
A
Loosen screws (A) and remove cover.
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
60
30
Secs.
0
60
30
Secs.
0
B
Probe Wires
B
Control Box
B
B
• Disconnect probe wires (red, blue, yellow) from circuit board.
• Remove 4 screws (B) connecting control box to brackets, lifting control box from brackets.
Remote Mounting of the Control Box
Probes
Disconnect wires from probes.
Cover Plate
Brackets
C
C
C
C
C
C
Offset Connector
• Remove 6 screws (C) connecting brackets and cover plate to probe housing.
• Remove offset connector from cover plate.
7
Only loosen upper nut to remove probe wire.
NOTE
Upper Nut
8
• Mount Control Box in a suitable location near
the boiler’s main electrical panel.
• Install electrical conduit between Probe Housing and Control Box.
• Pull four (4) wires through conduit.
Boiler sight glass must be visible from location of Control Box and must be within 25 feet of Control Box.
NOTE
Refer to and follow local codes and standards when selecting conduit and electrical fittings. Wires from Probe Housing to Control Box must be in their own conduit. If they are run in conduit with other wires, there may be interference that can affect the performance of the control.
NOTE
Wire must be 18 AWG stranded with glass braided silicone jacket (UL 3071) suitable for high temper­ature (200˚C) service.
NOTE
9
Screws
Plate Ground
Blue/Top
Yellow/Middle
Red/Bottom
Connect wires between Control Box and Probes as follows.
Pr
obes Control
Top/Blue Top/Blue Middle/Yellow Middle/Yellow Bottom/Red Bottom/Red Plate Ground Chassis Ground
• Attach cover plate to probe housing.
• Use knockout plug from probe housing to plug the hole in the cover plate.
• Proceed to Electrical Wiring Section to complete wiring to Burner and Pump/Valve circuits.
Wire connections at Probes (1/4” Ring Terminal) and Control Panel (22-18 Female Spade) must be made with connectors suitable for high temperature (200˚C) service.
NOTE
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
60
30
Secs.
0
60
30
Secs.
0
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
60
30
Secs.
0
60
30
Secs.
0
Probe wires
Control Box
Chassis Ground
10
STEP 4 - Electrical Wiring
•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.
• Boiler manufacturer schematics should always be followed. In the event that the boiler manufacturer’s schematic does not exist, or is not available from the boiler manufacturer, refer to the schematics provided in this document.
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
L
Cover Removal and Installation Procedure a. To remove cover, use a flatblade screwdriver to
loosen screws and remove the cover (K).
b. To reconnect cover, slide over brackets and tighten
screws using a flatblade screwdriver.
c. Following the appropriate wiring diagram (refer to
page 11) 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 2” (13mm) between connector fittings and electrical live metal parts.
Circuit Board Layout
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
60
30
Secs.
0
60
30
Secs.
0
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
0 60
30
Secs.
0
Probe Connections
Bottom
Red
Middle Yellow
To p
Blue
0-60 Second Adjustable Burner Off Delay
110 Volt Input
from Boiler
Circuit
Manual Reset
(If applicable)
Low Water
LED Red
Powe r
LED
Green
Test
Switch
Burner
Te r minals
Pump
Te r minals
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
Probe LED's
K
11
PUMP OPERATION
BURNER OPERATION
FROM BURNER OR ALARM
CONTROL CIRCUIT
TO ALARM
CONTROL CIRCUIT
TO BURNER
CONTROL CIRCUIT
FROM PUMP UP
CONTROL CIRCUIT
TO PUMP UP
CONTROL CIRCUIT
NEUTRAL
HOT
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
g
f
e
d
c
b
a
• Connect wire “a” from power supply to terminal “H”.
• Connect wire “b” from neutral supply to terminal “N”.
• Connect wire “c” from pump control circuit to terminal “PNO”.
• Connect wire “d” from pump control circuit to terminal “PCOM”.
• Connect wire “e” from burner control circuit to terminal “BNO”.
• Connect wire “f” from alarm control circuit to terminal “BNC”.
• Connect wire “g” from burner or alarm control circuit to terminal “BCOM”.
WIRING DIAGRAMS Low Water Cut-Off, Alarm and Pump Up Control
PUMP 1 OPERATION
PUMP 2 OPERATION
FROM PUMP #1
CONTROL CIRCUIT
FROM PUMP #2
CONTROL CIRCUIT
TO PUMP #2
CONTROL CIRCUIT
TO PUMP #1
CONTROL CIRCUIT
NEUTRAL
HOT
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
f
e
d
c
b
a
• Connect wire “a” from power supply to terminal “H”.
• Connect wire “b” from neutral supply to terminal “N”.
• Connect wire “c” from pump #1 control circuit to terminal “PNO”.
• Connect wire “d” from pump #1 control circuit to terminal “PCOM”.
• Connect wire “e” from pump #2 control circuit to terminal “BNC”.
• Connect wire “f” from pump #2 control circuit to terminal “BCOM”.
Dual Pump Control
VALV E SPRING CLOSED
BURNER OPERATION
VALV E DRIVE TO OPEN
• Connect wire “a” from power supply to terminal “H”.
• Connect wire “b” from neutral supply to terminal “N”.
• Connect wire “c” from valve control circuit to terminal “PNO”.
• Connect wire “d” from valve control circuit to terminal “PCOM”
• Connect wire “e” from burner control circuit to terminal “BNO”.
• Connect wire “f” from alarm control circuit to terminal “BNC”.
• Connect wire “g” from burner or alarm control circuit to terminal “BCOM”.
Motorized Valve and Low Water Cut-Off
FROM VALVE
CONTROL CIRCUIT
TO VALVE
CONTROL CIRCUIT
NEUTRAL
HOT
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
d
c
b
a
FROM BURNER OR ALARM
CONTROL CIRCUIT
TO ALARM
CONTROL CIRCUIT
TO BURNER
CONTROL CIRCUIT
g
f
e
12
STEP 5 - Testing
Procedure
OFF
ON
Tu rn on power to the boiler and pump circuits. With the boiler empty, the control will be activated (Green LED On) and the pump should turn on. The burner should stay off (Red LED On).
NOTE: If Green and Red LED’s flash alternately, the probes are not con­nected in sequence. Turn off power and check probe wires for proper connection.
Green light on: Unit has power
Red light on: Boiler water dropped below the bottom probe for longer than the adjustable time delay
setting. The burner has shut down.
Red light flashing every second: Boiler water was below the middle probe for more than three
minutes and the burner has shut down.
Auto reset units will automatically reset when the boiler water returns to the middle probe.
Manual reset units must be manually reset after boiler water returns to the middle probe.
Red light and green light flashing alternately every 1/2 second. Probes are out of sequence.
Unit has shut down. Unit will automatically reset when condition has cleared or been corrected.
Red light and green light flashing simultaneously every 1/2 second: The PCB is too hot and the unit
has shut down. The unit will automatically restart when the PCB has cooled sufficiently.
• When using the “TEST” button, the green light will flash once per second during the time delay interval. The time delay setting can be determined by counting the number of flashes.
Green Light – Shows status of top probe Yellow Light – Shows status of middle probe Red Light – Shows status of bottom probe
• If the light is on, the probe is in water and probe resistance is well below the threshold.
• If the light is flashing every 1/2 second, the probe is in water, but probe resistance is near (just below) the threshold.
• If the light is flashing every 2 seconds, the probe is out of water, but probe resistance is near (just above) the threshold.
• If the light is off, the probe is out of water and probe resistance is well above the threshold.
IMPORTANT: Follow the boiler manufacturer’s start-up and operating instructions along with all applicable codes and ordinances.
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
Exterior Lights
Interior Lights
13
Adjusting Burner Delay (DOB)
The boiler should begin to fill with water.
NOTE: If water does not start filling the boiler, immediately turn off the the boiler and make the necessary corrections.
For Automatic Reset Models:
When the water level reaches the level of the middle probe, the burner circuit should be acti­vated and the Red LED should turn off. (Pump #2 should turn off with Dual Pump Applications).
For Manual Reset Models:
The reset button must be pushed to activate the burner circuit when water reaches the level of the middle probe.
When the water level rises to the level of the top probe, the pump relay will be de-activated. Depending on the application, this will either turn off the pump or close a valve.
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
60
30
Secs.
0
60
30
Secs.
0
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
0 60
30
Secs.
0
Probe Connections
Bottom
Red
Middle Yellow
Top
Blue
0-60 Second Adjustable Burner Off Delay
110 Volt Input
from Boiler
Circuit
Manual Reset (If applicable)
Low Water
LED Red
Powe r
LED
Green
Test
Switch
Burner
Te r minals
Pump
Te r minals
BCOM
BNC
BNO
PCOM
PNC
PNO
N
H
Probe LED's
The number of seconds that water must be off the bottom probe before the burner will turn off is adjustable from 0 to 60 seconds with the unit factory set at 0 seconds. To adjust, turn the adjusting screw clockwise using a small flatblade screwdriver to the delay time desired.
Follow the blow down procedure found on page 15 to verify operation.
INSTALLATION COMPLETE
If the delay time is too long, the manual reset sec­ondary LWCO may turn off the boiler before this con­trol turns off the boiler. If this occurs, shorten the time delay by turning the adjustment screw counter-clock­wise from the new setting.
NOTE
14
Troubleshooting
Green LED does not turn on.
• There may be no power to the unit. Check wiring connected to ‘H’ and ‘N’ terminals on circuit board. Verify that the control is being powered when the boiler power is turned on.
Red & Green LEDs flash alternately every 1/2 second.
• The probes are out of sequence. Check probe wires and connections.
• The control head flange is not installed properly. “A” or “B” tabs must be installed at bottom of body.
Red & Green LEDs flash simultaneously every 1/2 second.
• The temperature at the circuit board is higher than 170˚F. Removing the control box cover may cool the control enough for it to operate. If the control works with the cover removed, the control box should then be mounted remotely.
Pump does not turn off when water level is above top probe.
• The probes may be fouled with dirt, scale or rust. Remove head assembly to inspect probes.
•The wiring connections for the pump may not be connected properly. Check wiring at terminals.
Pump does not turn on when water level is below the middle probe.
• The probes may be fouled with dirt, scale or rust. Remove head assembly to inspect probes.
•The wiring connections for the pump may not be connected properly. Check wiring at terminals.
Burner does not turn off when water level is below bottom probe.
• The probes may be fouled with dirt, scale or rust. Remove head assembly to inspect probes.
•The wiring connections for the pump may not be connected properly. Check wiring at terminals.
• Make sure time delay is not causing delay of burner off.
The 150E control does not turn off the burner before the secondary (manual reset LWCO) turns off the burner.
•The burner off time delay (DOB) may be set for too long of a delay.
During operation, the burner does not turn off when the water level is below the bottom probe.
•The burner off time delay (DOB) may be set for too long of a delay.
• The boiler water may be priming or foaming. Clean boiler water and/or consult with chemical treatment specialist.
During operation, the burner turns off even when the pump has turned on or the motorized valve has opened.
• Pump capacity may not be sufficient or there may be restrictions in the feedwater piping. Check pump capacity and piping.
• The motorized valve stroke-to-open time may be too long. Check valve motor timing.
15
Valve #1
Valve #2
BLOW DOWN PROCEDURE:
When blowing down a control at pressure, the blow down valves should be opened slowly. The piping needs to be warmed up and stagant water in the drain piping needs to be pushed out. Suddenly opening a blow down valve causes steam to condensate, which creates water hammer. Damage to components can occur when water hammer occurs due to improper blow down piping.
For these reasons, McDonnell & Miller recommends a dual valve blow-down system for each control.
Blow down the low water cut-off when the water level is at its normal level (pump/valve off) and the burner is on.
• Open the upper “Positive Shut-off Ball Valve” (#1).
• Slowly open lower “Throttling Gate Valve” (#2).
• With both valves open, the water level will drop in the sight glass.
• When the water falls below the level of the middle probe, the pump or valve should turn ON.
• When the water falls below the level of the bottom probe, the burner should turn OFF. NOTE: The Red LED will turn ON to indicate low water condition.
• Slowly close the lower “Throttling Gate Valve” (#2).
• The water level should begin to rise and the burner should turn ON (Red LED turns off) when the level is at the middle probe. The pump or valve should turn OFF when the water level rises above the top probe postion.
NOTE: On manual reset models, the red reset button will need to be pressed after the water level is restored to the level of the middle probe before the burner will operate.
• Close the upper valve “Positive Shut-off Ball Valve” (#1).
• Observe that the water level returns to its normal level before leaving the site.
To prevent serious personal injury from steam pipe blow down, connect a drain pipe to the control opening to avoid exposure to steam discharge.
Failure to follow this caution could cause personal injury.
!
CAUTION
MAINTENANCE
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.
Disassemble and inspect annually.
Inspect the float/probe chamber and equalizing piping annually.
Remove all sediment and
debris from chamber and/or equalizing piping.
• Inspect and clean probes. Use a non-abrasive
cloth to clean probes and water-side of probe-mounting flange. Replace head mechanism and probes if probes are worn, corroded or have excessive coating of scale or rust that cannot be easily cleaned off.
Replace head mechanism every 5 years.
More frequent replacement may be required when severe conditions exist.
Replacement parts are available from your local authorized McDonnell & Miller Distributor. The use of parts or components other
than those manufactured by McDonnell & Miller will void all warranties and may affect the units' compliance with listings or regulating agencies.
WARNING
DO NOT REMOVE PROBES FROM FLANGE. Replace probe flange assembly if probe Teflon
®
insulation is broken, torn
or frayed.
NOTE
The probes may need to be inspected and cleaned more frequently on systems where there is the potential of coating build-up on the probes.This includes systems:
• With high raw water make-up
• With no condensate return
• With untreated boiler water
• Where significant changes have been made to the boiler-water chemical treatment process
• With oil in the boiler water
NOTE More frequent blow-down may be necessary due to dirty boiler water and/or local codes.
NOTE If this sequence of actions does not occur, as described, immediately close all valves, turn off the boiler and correct the problem. To correct the problem, inspection/cleaning of all probes may be required.
ITT
8200 N. Austin Ave. Morton Grove, IL 60053 tel: 847-966-3700 fax: 847-966-9052 www.mcdonnellmiller.com
McDonnell & Miller
©2007 ITT Corporation
Printed in U.S.A. 5-07 210496
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