Testing & service, Continued), Trouble-shooting – Emerson 7ADTB User Manual

Page 8: Table b. trouble-shooting checks, Maintenance handle

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TESTING & SERVICE

(continued)

2--2

TROUBLE-SHOOTING

Note any optional accessories that may be furnished on

the 7ADTB and review their operation. Refer to any

separate drawings and/or instructions that may be packed

with the 7ADTB. See Table B.

Hazardous voltage capable of causing shock,

burns, or death is used in this switch.

Do not touch the power or load terminals

of the bypass switch or transfer switch!

Table B. Trouble-Shooting Checks.

PROBLEM

CHECK IN NUMERICAL SEQUENCE

PROBLEM

1 OPERATION

2 GEN-SET

3 VOLTAGE

Engine–generator set does

not start when the Transfer

Control switch is turned and

held in Transfer Test position

or when normal source fails.

Hold Transfer Test switch 15

seconds or the outage must

be long enough to allow for

Feature 1C time delay plus

engine cranking and starting.

Starting control must be in the

automatic position. Batteries

must be charged and

connected. Check wiring to

engine starting contacts.

---

Transfer switch does not

transfer the load to the

emergency source after the

engine–generator set starts.

Wait for Feature 2B time delay
to time out.

Generator output circuit

breaker must be closed.

Generator frequency must be

at least 95% of nominal (57 Hz
for a 60 Hz system.) *

Voltmeter should read at least

90% of nominal phase to

phase voltage between

terminals EA and EC (or EL1

and EL2 for 2 pole switches)*

Transfer switch does not

transfer the load to normal

source when normal returns

or when the Transfer Control

switch is released.

Wait for Feature 3A time delay

to time out.

---

Voltmeter should read at least

90% of nominal phase to

phase voltage between

terminals NB and NC, NC and

NA, and NA and NB (or NL1

and NL2 for 2 pole switches).

Gen. does not stop after load

retransfer to normal source.

Wait for Feature 2E time delay

to time out.

Starting control must be in the

automatic position.

---

Load Disconnect Active light

comes on.

Wait for load disconnect time

delay to time out.

Explanation: Transfer switch in delayed transition transfer mode.

Load disconnect time delay is adjustable from 0 to 5 min. 59 sec.

Load Disconnect Active light

stays on longer than 6 min.

Check load disconnect time

delay setting. Call ASI.

Explanation: Transfer switch contacts are open longer than 5

min. 59 sec (maximum setting). Load remains disconnected.

* These are factory settings. Refer to Controller’s User’s Guide.

If the problem is isolated to circuits on the controller or the transfer switch, call your local ASCO Power Technologies

sales office or ASI: in the United States, call 1–800–800–2726 or in Canada call 1–888–234–2726. Furnish the Serial No.,

Catalog No., and Bill of Material (BOM) No. from the transfer switch nameplate.

MAINTENANCE HANDLE

Bypass and isolate the Transfer Switch before

using the maintenance handle! See pages

3–1 through 3–4. Remove the maintenance

handle after using it; store it inside.

1. Bypass, isolate, and withdraw the transfer switch

(pages 3–1 through 3–4). Then locate and remove the
maintenance handle from the clip (inside lower left
side). Insert the handle onto the shaft on the left side
of the operator of the transfer switch See Figures
2–1, 2–2, 2–3 and Table C.

2. Move the maintenance handle up or down as shown

to manually operate the transfer switch. Operate

both upper and lower contact shafts. Observe the
window indicators (right side). Remove the mainte-
nance handle and store it on the lower left side.

window

indicators

O is open

C is closed

contact

position

indicators

(right side)

Emergency contacts

(upper shaft)

Normal contacts

(lower shaft)

Figure 2–1. Contact position indicators.

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