Watlow Power Series Rev H - Manual (Page 12)

Power Series Output Rating Curves
Natural Convection
All curves are at 100% on and with 90°C rated load wire and line wire connected. Note that each chart is
slightly different on the amperage scale. The safe operating region is from 1 amp up to the specific curve for
the output amperage code selected. For example: N25 Single Phase is rated up to 140 amps at 50°C; N30
Single Phase is rated for 165 amps at 50°C.
3 Phase, 3-Leg and 3-Zone Multizone
Natural Convection at 100% On
25
30
35
40
45
50
55
60
65
Current (Amps) into a Resistive Load
N20 N25 N30
Enclosure Internal
Ambient Temperature
° C
60 140 70 80 90 100 110 120 130 50
3 Phase, 2-Leg and 2-Zone Multizone
Natural Convection at 100% On
25
30
35
40
45
50
55
60
65
Current (Amps) into a Resistive Load
60 140 70 80 90 100 110 120 130
N20 N25 N30
Enclosure Internal
Ambient Temperature
° C
Single Phase Natural Convection at 100% On
25
30
35
40
45
50
55
60
65
Current (Amps) into a Resistive Load
80 210 90 100 110 120 130 140 150 170 180 190 200 160
N20 N25 N30 Enclosure Internal
Ambient Temperature
° C
2 . 6 ■ I n s t a l l a t i o n Wa t l o w P o w e r S e r i e s