PRODUCTS

ASCO 7000 Series External Power Connections 

Transfer Switch Configurations
7A TS, 7N TS, 7A DTS, 7A CTS, 7N DTS, 7N CTS
Sizes of UL-Listed Solderless Screw-Type
Terminals for External Power Connections

Switch Rating
(amps)		 Max number of
Conductors per Terminal		 Range of AL-CU
Conductor Sizes
30-230 ATS, NTS3 One #14 to 4/0 AWG
150 DTS, CTS One
Two		 #4 AWG to 600 MCM
#1/0 AWG to 250 MCM
260-400 One
Two		 #4 AWG to 600 MCM
#1/0 AWG to 250 MCM
600 Two #1/0 AWG to 600 MCM
800-12001 Four #1/0 AWG to 600 MCM
1600-20002 Six #1/0 AWG to 600 MCM
30002 Twelve #1/0 AWG to 600 MCM
40002 Twelve #2/0 AWG to 600 MCM

NOTES:

1. Unit is designed for top cable entry of emergency and load and bottom entry of normal. Optionally, the switch may be supplied with reverse source and/or bottom entry load, when specified.
2. All main terminals are rear connected.
3. 200 and 230 amp rating for copper conductors for transfer switch configurations only.

Transfer/Bypass Configurations
7A TB, 7N TB, 7A DTB, 7A CTB, 7N DTB, 7N CTB
Sizes of UL-Listed Solderless Screw-Type
Terminals for External Power Connections

Switch Rating
amps		 Max No. of Conductors
per Terminal		 Range of AL-CU
Conductor Sizes
150, 260, 400 One
Two		 #4 AWG to 600 MCM
#1/0 AWG to 250 MCM
600 - 800 Three #2 AWG to 600 MCM
1000 - 12001 Four #1/0 AWG to 250 MCM
1600 - 20001 Six #1/0 AWG to 600 MCM
30001 Ten #1 AWG to 750 MCM
40001 Twelve #1 AWG to 750 MCM

NOTES:

1. All main terminals are rear connected.

External Power Connection Detail for 200-400 Amp Switches

The chart below should be reviewed on all applications when coordinating the power cabling requirements with the standard ASCO lug connections. Standard ASCO lugs are UL listed for connecting copper or aluminum conductors in compliance with the NEC. However, the “D” frame 200 and 230 amp switches must be connected with copper cable (except for certain single-phase applications as noted below) to obtain the full 200 or 230 amp rating. The “E” frame switch should be specified. If the standard lugs on the “D” switch will not accept the cable size required.

Frame Switch
Rating
(amps)		 Ranges of Al - Cu Wire
Sizes		 Cable
Type		 NEC Cu @ 75ºC NEC Al @ 75ºC
D 200 (1) #14 to 4/0 AWG Cu Onlyl 3/0 250MCM
D 230 (1) #14 to 4/0 AWG Cu Onlyl 4/0 300MCM
E 260 (2) 1/0 AWG to 250 MCM
or (1) #4 AWG to 600 MCM		 Cu or AI (1) 300 MCM
(2) # 1		 (1) 400 MCM
(2) 2/0
E 400 (2) 1/0 AWG to 250 MCM
or (1) #4 AWG to 600 MCM		 Cu or AI (1) 600 MCM
(2) 3/0		 (1) 900 MCM
(2) 250 MCM

1. For the main power feeder in residential 240 volt, single phase applications (between the meter and panelboard only), NEC paragraph. 310.15(B)(6) allows the switch to be connected with aluminum cables as shown in Table 310.15(B)(6) below. The lug size on the 200 amp switch was increased from 3/0 to 4/0 specifically for this type of application, since most service entrance feeders available from electrical supply houses are aluminum.

Table of Conductor Types and Sizes2
For 120/240 Volt, 3 wire, Single Phase Dwelling Services and Feeders 

Conductor ( AWG or kcmil)
Copper Aluminum or Copper -
Clad Aluminum		 Service or Feeder
Rating (Amperes)
4 2 100
3 1 110
2 1/0 125
1 2/0 150
1/0 3/0 175
2/0 4/0 200
3/0 250 225
4/0 300 250
250 350 300
350 500 350
400 600 400

2NFPA 70 - National Electric Code - Table 310.15(B)(6)