Automatic Electric Alternators

Class 9039 alternators are used with two separately enclosed motor starters to alternate the operation of the pump motors of a duplex pump installation. Duplex installations are made to provide a stand-by pump if one set of equipment fails, and to provide additional capacity if the load becomes too great for a single pump. Pump wear is equalized by automatically alternating the first pump to start on each successive operation. Class 8501 Type X machine tool relays are used in Class 9039 Type X alternators to provide maximum reliability and life.

Table 23.132:

AC Power Supply: 110–600 Vac, 50–60 Hz

General Purpose
Enclosure
NEMA 1

Watertight
Enclosure
NEMA 4

Watertight, Dusttight and
Corrosion-Resistant
Glass-Polyester Enclosure
NEMA 4X

Dusttight Enclosure
NEMA 12

For Hazardous Locations
Class 1, Group D
NEMA 7

a	Voltage code must be specified to order this product. Refer to standard voltage codes listed below and insert as shown in How To Order.

Table 23.133:

NEMA
Rating

Continuous
Amperes

120
240
480
600

A600

60
30
15
12

7200
7200
7200
7200

6
3
1.5
1.2

720
720
720
720

10
10
10
10

Operation

1.	The two pilot devices (A and B) must be double pole. Pilot device A is set to close at a lower liquid level than B.

2.	The alternator operates first one pump and then the other on each successive closing of pilot device A.

3.	After pilot device A closes, if the liquid continues to rise and reaches the level at which pilot device B is set, both pumps will operate.

4.	With one pump running, if its disconnect means is opened, an overload relay trips, or the starter is de-energized for any reason, the other pump will automatically be started. If the pump satisfies the demand and is shut off, it will restart when pilot device B closes.

Approximate Dimensions

9039 XO1 (The 9039 XG1 uses the 9991 LG1 enclosure. Other enclosed devices use Class 8502 size 0 & 1 enclosures. Dimensions on pages 16-107 through 16-109).

Table 23.134:

Voltage Codes

AC Voltages—Hz

Code

24–60

V01

24–50

V12

120–60/110–50

V02

208–60

V08

240–60/220–50

V03

277–60

V04

480–60/440–50

V06

600–60/550–50

V07

Other Voltagesb

V99b

b	Specify voltage and frequency.


	File CCN	E78403NKCR

Table 23.135:

How to Order

To Order Specify:

Catalog Number

▪	Class Number

▪	Type Number

▪	Voltage Code

Voltage Code


I12	Discount Schedule

Related Topics: Replacement Coils (Use 8501 Type X Relay coils) page 23-26

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