Quadlogic MiniCloset-5c, Installation Manual

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Chapter 4 Installation
© COPYRIGHT 2009
Quadlogic Controls Corporation
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1. Every CT MUST be connected to an MCI input which is referenced to the correct
phase (see Figure 4-4).
2. The meter can be configured in two ways:
a.
Commercial: (6) 3-phase meters or (8) 3-phase meters
For these installations, the meter measures (6) or (8) 3-phase loads. The 3 CTs
from each load (one for each phase) must be connected to 3 adjacent inputs, as
shown in Figures 4-4.
Installation Notes
CRITICAL:
The Phase Association and Polarity of the current transformers must be followed or meter will
not be installed correctly.
Current transformers (CTs) are used to measure the current drawn by the loads to be
metered. Within the meter, the current reading from the CT is combined with the voltage
reading for the correct voltage phase to calculate the energy reading. CTs must be in phase
with reference voltage. The MCI inputs are each associated with a particular voltage phase in
an A-B-C order. Input 1 is a phase A CT, input 2 is a phase B CT, input 3 is a phase C CT,
input 4 is a phase A CT, and so on in A-B-C-A-B-C order.
Figure 4-4. CT phase association for 3-phase, 4-wire loads
For example, a current transformer which measures a load supplied by phase A must be
installed on CT1, CT4, CT7, etc. Current transformers which measure a load supplied by phase
B must be installed on CT2, CT5, CT8, etc. Lastly, current transformers which measure a load
supplied by phase C must be installed on CT3, CT6, CT9, etc.
1. For Commercial (designated with “C”) 3-phase/4-wire model, each A-B-C combination
is a single meter point:
-
Meter #1 (M#1) is CT1, CT2, and CT3
-
Meter #2 (M#2) is CT4, CT5, and CT6
-
Repeat for M#3 to M#8