50HCQA
Legend and Notes for Table 10
LEGEND:
BRKR
CO
DD
DISC
FLA
IFM
LRA
MCA
PE
PWRD CO
UNPWR CO
NOTES:
1.In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. Canadian units may be fuse or circuit breaker.
2.Unbalanced
Never operate a motor where a phase imbalance in supply voltage is greater than 2%. Use the following formula to de- termine the percentage of voltage imbalance.
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
average voltage
Example: Supply voltage is
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage = | (224 + 231 + 226) | = | 681 | |
|
| |||
3 | 3 | |||
|
|
=227
Determine maximum deviation from average voltage. (AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v (AC) 227 – 226 = 1 v Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% Voltage Imbalance | = 100 x | 4 | |
| |||
227 | |||
|
| ||
| = 1.76% |
|
This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact your local electric utility company immediately.
Economizer | 2 Position Damper | Unit Without Economizer or | |
2 Position Damper | |||
|
| ||
|
| C08631 |
Fig. 65 - EconoMi$ert IV Wiring
Step 11 — Adjust Factory-Installed Options
Smoke Detectors —
Smoke detector(s) will be connected at the Central Terminal Board (CTB), at terminals marked “Smoke Shutdown”. Remove jumper JMP 3 when ready to energize unit.
EconoMi$er IV Occupancy Switch —
Refer to Fig. 65 for general EconoMi$er IV wiring. External occupancy control is managed through a connection on the Central Terminal Board.
If external occupancy control is desired, connect a time clock or remotely controlled switch (closed for Occupied, open for Unoccupied sequence) at terminals marked OCCUPANCY on CTB. Remove or cut jumper JMP 2 to complete the installation.
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