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Electronic Theatre Controls Inc

What are LMI and ETC ASTS and what is the difference?

What is it

ASTS Alternate Source Transfer Switch and the L86 ECX Transfer Cabinet ETC Part # 1092A100x (The X indicates the # of transfer circuits)

Transfers the hot and neutral from 1 to 4 circuits from the dimmer rack to an alternative power source when it senses loss of normal power. It is a simple circuit of time delay relays and contactors. 

CB1     10 Amp Normal Power feed (sense lines)
CB2     10 Amp Control feed off the Emergency Power feed.
CB3-6  20 Amp Individual circuits Emergency Power feed.

Difference

The ASTS and the L86 ECX are identical except the early version of the L86 ECX ETC The L86 EC had three control relays. Later the ETC ASTS only has two control relays. The function of L86 ECX relays RL10 and RL11 have been changed to RL9 and RL 10

L86 ECX Control Relays

RL9 Control transfer relay, makes sure the timing relays always have power and starts the clock for transfer timer.

RL10 Delay timing relay from loss of normal power to time of transfer of the loads to emergency.

RL11 Delay timing relay from return of normal power to the transferring of the loads back from emergency. This insures that normal power is stable before transferring the loads back to the dimmer system.

SEE ATTACHMENTSL86_EC2_drawing.pdf
SEE ATTACHMENTSL86_EC4_drawing.pdf

ETC ASTS Control Relays

RL 9 Delay timing relay from loss of normal power to time of transfer of the loads to emergency.

RL10 Delay timing relay from return of normal power to the transferring of the loads back from emergency. This insures that normal power is stable before transferring the loads back to the dimmer system.

SEE ATTACHMENTSASTS_EC1.pdf
SEE ATTACHMENTSASTS_EC2.pdf
SEE ATTACHMENTSASTS_EC3.pdf
SEE ATTACHMENTSASTS_EC4.pdf

 

 

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