Emerson 3000 Furnace User Manual


 
Installation (Applicable to all Models)
19
Figure 12 Electrical connections
1. Electric conduit knockouts on top and bottom of electric box. Knockout size 1-3/4" (44.5mm).
2. Three-phase connection. Electric service connection terminals when factory disconnect is NOT
supplied.
3. Three-phase connection. Electric service connection terminals when factory disconnect switch
is supplied.
4. Factory-installed disconnect switch. (Optional).
5. Three-phase electric service field-supplied.
6. Earth ground connection (50/60Hz). Connection terminal for field-supplied earth grounding
wire.
7. Earth ground bar (50Hz only). Connection terminals with factory ground from each high
voltage component for field supplied earth grounding wire.
8. Control and monitoring section of electric box.
9. Remote unit shutdown. Replace existing jumper between Terminals 37 + 38 with normally
closed switch having a minimum 75VA, 24VAC rating. Use field-supplied Class 1 wiring. Two
additional contact pairs available as an option (labeled as 37B & 38B, 37C & 38C). Replace
existing jumper for appropriate pair as done for 37 & 38.
10. Special alarm connections. Field-supplied 24V Class 1 wiring for special alarm. Connection
made by adding normally open contacts between terminals 24 + 50. Special alarm connections
may be factory-wired or field-wired. See schematic for factory wired special alarms. For
field-wired special alarms, use 24V Class 1 wiring to connect normally open contacts between
Terminals 24 & 50, 24 & 51, 24 & 55, or 24 & 56.
11. SiteScan connection. Terminals 77 (-) and 78 (+) are for connection of a 2-wire, twisted pair,
communication cable (available from Liebert or others) to optional Liebert SiteScan
®
.
12. Remote condensing unit connection. Field-supplied 24V Class 1 wiring to remote condensing
unit Terminals 1, 2, 3, & 4 from (R2) relay (split system only).
13. Smoke detector alarm connections. Field-supplied 24V Class 1 wiring to remote alarm
circuits. Factory-wired contacts from optional smoke detector are #91-comm., #92-NO, and
#93-NC.
14. Common alarm connection. Field-supplied 24V. Class 1 wiring to common alarm Terminals
75 + 76 (and optional 94 + 95, and 96 + 97), which are factory-connected to common alarm relay
(R3).
88
89
84
85
82
83
91 92
93
1234
7877
3738B37B38C37C9796
95
94
7675
565551
50
24
38
Electrical Handy Box
(factory-installed with cover;
inside unit on top for upflow
and on base for downflow.)
Terminal Block - for customer connections
1
2
3
4
5
15
1
6
7
8
DPN000354
Rev. 01
14 14 9 9 10 11 13 12 16 17 18
70
73
72
71