background image

D

NN

d.

To prevent serious personal injury from steam and hot water during blow-down, connect piping to
the discharge side of the blow-down valve to avoid exposure to steam discharge.

Failure to follow this caution could cause personal injury.

!

CAUTION

When the water level is at its normal level
and the burner is on, 

slowly

open the blow

down valve (NN) until it is fully open. Watch
the gauge glass (D) to see that the water
level drops. Close the valve after verifying
that the pump comes on and the burner
shuts off. If this does not occur, immediately
shut off the boiler and correct the problem
and retest.

INSTALLATION COMPLETE

1

3

/

8

"

(35 mm)

D

MM

c.

Continue watching the gauge glass (D)
to see that the water continues to rise to
approximately 1

a

” (35mm) above the

horizontal cast line (MM). The pump
should shut off.

10

Summary of Contents for McDonnell & Miller 42S-N Series

Page 1: ...INSTRUCTION MANUAL MM 231G...

Page 2: ...ATER LINE PUMP OFF BURNER OFF BURNER CUT OFF LEVEL AT CAST LINE 1 3 8 35mm CUT OFF LEVEL NORMAL BOILER WATER LINE CUT OFF LEVEL PUMP OFF PUMP ON 3 4 19mm OPERATION Maximum Pressure 50 psi 3 5 kg cm2 E...

Page 3: ...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 al...

Page 4: ...as depicted in the diagram to the bottom right OR If gauge glass tappings F and G are greater than 14 356 mm apart invert the black Y casting H as depicted in the diagram to the bottom right and inst...

Page 5: ...P Screw reducer bushing Q nipple R and blow off valve S into bottom 1 NPT tapping T Screw lower union tailpiece V with nut U into either 1 2 NPT lower tapping W X Screw 1 2 NPT pipe plug into unused...

Page 6: ...rient 1 2 NPT tapping FF with 1 2 tapping on control GG b Mount and pipe control HH on vertical equalizing pipes JJ at the required elevation as determined in Step 1 c Install gauge glass and other tr...

Page 7: ...h could result in property damage personal injury or death WARNING Switch Operation Boiler feed pump off burner on Boiler feed pump on burner on Boiler feed pump on burner off 1 2 5 6 1 2 5 6 1 2 5 6...

Page 8: ...n NOTE To help insure most effective operation balance boiler feed pump s to deliver required water feed rate to match boiler steaming requirements 1 Main Line Switch For burner circuits within the sw...

Page 9: ...ating ranges are shown on page 2 in the Operation section OFF ON If the burner comes on immediately turn the boiler off and make the necessary corrections Failure to follow this warning could cause an...

Page 10: ...urner is on slowly open the blow down valve NN until it is fully open Watch the gauge glass D to see that the water level drops Close the valve after verifying that the pump comes on and the burner sh...

Page 11: ...s on NOTE Refer to page 2 for switch operating points Open upper valve 1 Slowly open the lower valve 2 Water in the sight glass should lower As the water in the sight glass lowers the pump should turn...

Page 12: ...ngs 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...

Reviews: