Overview of Primary Product

O r dering Info r m a t i o n
• For high capacity [up to 35,000 sq. ft. (3250m
2
)] low pressure
steam and hot water boilers with cold water feed
• Optional features
– No. 2 switch
– Manual reset
– Float block
• Proportional feed action
• Maximum water supply pressure 100 psi (7 kg/cm
2
)
• Maximum inlet water temperature 120˚F (49˚C)
• Maximum vessel pressure 35 psi (2.5 kg/cm
2
)
Series 51-S
Series 51-S-2
Water Feeders – Mech a n i c a l
Series 51-S/51-S-2
Mechanical Water Feeders/Low Water Cut-Offs
Dimensions, in. (mm)
Model Part Weight
Number Number Description lbs. (kg)
51-S 135600 Mechanical water feeder 36.5 (16.6)
51-S-2 135900 51-S w/No. 2 switch 37.3 (16.9)
51-S-2-M 136000 51-S-2 w/manual reset 37.3 (16.9)
51-SB 135700 51-S w/float block 41.8 (19.0)
51-SB-2 136300 51-SB w/No. 2 switch 41.8 (19.0)
51-SB-2-M 136100 51-SB-2 w/manual reset 43.7 (19.8)
A B C D E F
NPT NPT NPT
1 8
1
⁄
8
(203) 1 0
3
⁄
8
( 2 6 4 ) 5
3
⁄
4
(146) 1
3
⁄
4
C a p a c i t i e s
Electrical Ratings
Motor Switch Rating (Amperes)
Voltage Full Load Locked Rotor Pilot Duty
120 VAC 10.2 61.2
125 VA at
240 VAC 5.1 30.6
120 or 240 VAC
60 Hz
61
Boiler Controls
McDonnell & Miller
06. HotWtrLwco 50-61• 3/7/07 12:45 PM Page 61