Libertyville IL (847) 680-7400 FAX (847) 680-8169 www.ciitech.com
15
GENERAL PURPOSE RELAY
TYPE 157
FEATURES:
• The Type 157 relay is a rugged power driver offering superior 3/16”through air and 3/8”over-surface
spacing.
• An interlocked frame and contact block prevent contact misalignment during plug-in.
• Open or dust covered available with indicator lamps and push-to-operate buttons.
• A magnetic latching version provides a unique switchable core which cannot be falsely latched.
• All Midtex catalog Type 157 relays have UL & CSA Recognition as motor controllers through 600 VAC
• They provide through air spacing of 3/16”minimum and over-surface spacing of 3/8”minimum and are
recognized for 1/2 hp motor controller applications at 240/480/600 VAC (1/3 hp at 120 VAC).
• Chassis mounted open relays must employ 1/32”additional insulation between mounting surface and relay
to insure 1/2”over-surface and through air to the mounting surface.
• Sockets for the 157 relays are constructed to meet UL requirements for these ratings.
• UL File E38802 CSA LR54109
Voltage Ratings
Pick-up Voltage
Duty Cycle
Power Ratings*
Tem perature Rise*
Nominal
Max. Continuous
Nominal Voltage
25% overvoltage
1.7 VA
2.7 VA
1 & 2 Pole AC
2.0 VA
3.1 VA
3 Pole AC
1.2 W
1.9 W
DC
1 & 2 Pole AC
3 Pole AC
DC
Shock
Vibration
6 to 240 VAC 50/60 Hz 5 to 110 VDC
AC–85% of nominal
DC–75% of nominal
Rated for continuous duty
operation at 25% overvoltage
15 g’s, 11±1mS (non-operating test,
no mechanical damage)
0.1”DA or 10g’s, 10 to 55 Hz
(operating test, no contact chatter)
Material
UL & CSA Recognition Rating
1/8”Fine Sliver
(gold flash)
5 amp
3/16”Silver
Cadmium Oxide
10 amp
3/16”Silver
Cadmium Oxide
15 amp
(UL on 1 & 2PDT
only)
1/8”Fine
Sliver Gold
Diffused
Mag Blowout
(See Note)
-100
-200
-300
-700
-3MO
Nom inal Voltage
Resistance
(Ohm s±10% )
5
6
12
24
48
110
V
D
C
V
A
C
6
12
24
120
240
1 & 2PDT
6.0
21
75
2250
9100
3PDT
4.2
18
72
1700
7200
20
32
120
470
1800
10000
5 amp, 28 VDC/ 120/240 VAC, 80% pf
2 amp 480/600 VAC, 80% pf
1/8 hp 120 VAC
1/4 hp 240 VAC
2 amp 7.2 amp in rush, 24 VAC (SP devices)
10 amp, 28 VDC/ 120/240 VAC, 80% pf
1/3 hp 120 VAC
1/2 hp 277/240/480/600 VAC
36 LRA, 8.5 FLA, 18VDC
3 amp 480/600 VAC, 80% pf
10 amp 277VAC resistive
15 amp 277/240/120 VAC
10 amp 28 VDC
3 amp 480/600 VAC
1/3 hp 120 VAC
1/2 hp 240/480/600 VAC
600w Tungsten 120/240 VAC
5 amp, 28 VDC/ 120/240 VAC, 80% pf
2 amp 480/600 VAC, 80% pf
1/8 hp 120 VAC
1/4 hp 240 VAC
2 amp 7.2 amp in rush, 24 VAC (SP devices)
1 Form X 12A @ 150 VDC
2 Form A 7A @ 150 VDC
2 Form C 5A @ 150 VDC
Open
35°C
55°C
Enc.
45°C
65°C
Open
45°C
75°C
Enc.
60°C
85°C
Open
35°C
50°C
Enc.
40°C
55°C
*60 Hz operation
Increase values 20% for 50 Hz operation.
All ratings at 25°C ambient
Design and Construction
Recognized by UL for motor controllers up to 600 VAC in accordance with UL Standard
508, Industrial Control Equipment. Optional features include manual push-to-test button
and indicator lamp.
Insulation Material-High quality phenolic
W eight (approximate)-2.3 ounces (64 grams)— open relay
3.0 ounces (84 grams)— enclosed relay
Marking
Midtex name, part number, nominal voltage, and terminal identification are standard.
Customer marking optional.
Initial Contact Resistance–50 milliohms max.
Note: For Mag Blowout positive contacts are 7 and 9. Negative contacts are 1, 3, 4 and 6.
