Wiring Brochure

© 2008 W 325 - 12/08 8 of 12
Use the supplied Job Records to determine if an external
24 V (ac) transformer is required.
If the combined total 24 V (ac) load exceeds 53 VA, an
external NEC / CEC Class 2 transformer is required.
1. Determine the number of zones (thermostats and zone
valves) that require an external transformer.
2. Choose a transformer with a VA rating sufficient to
operate these zones. (Thermostats and Zone Valves)
3. Mount and wire the external transformer according to
the manufacturer’s instructions.
4. For each of the selected zones, connect the thermostat’s
R wire to the external transformer’s 24 V (ac) R output.
(Do not use the 325’s R terminals)
5. Connect the C terminal of the external transformer’s
24 V (ac) output to terminal 60 (C) on the Zone Expansion
Module.
Note: For each zone using this external transformer,
only the tN4, C and W terminals from the thermostat are
connected to the Zone Expansion Module.
Wiring an External Transformer Terminal 72
Adding Extra VA
Example: Zones C1, C2, C3 operate off internal 325 transformer.
Zones C4, C5, C6 operate off external 24 V (ac) NEC / CEC Class 2 transformer.
tN4 C R Rh1 W1
tN4
Thermostat
tN4 C R Rh1 W1
tN4
Thermostat
tN4 C R Rh1 W1
tN4
Thermostat
tN4 C R Rh1 W1
tN4
Thermostat
C
C
R
R
LN
NEC / CEC
Class 2
Transformer
24 V (ac)
tN4 C R Rh1 W1
tN4
Thermostat
tN4 C R Rh1 W1
tN4
Thermostat
Valve Valve Valve Valve Valve Valve
N
Zone Group
89 90
Pmp C
tN4
Meets Class B:
Canadian ICES &
FCC Part 15
5 A (max)
Zone Expansion Module 325
tektra 998-01
Relay Rating: 115 V (ac) 5 A
24 V (ac) Fuse: T2.5 A 250 V
Power
Zone Group Pump C
H7001B
Zone C1
Zone C2
Zone C3
Zone C4
Zone C5
Zone C6
51 52 53 54 55 56 57 58 59 60 61 62
CCWWRRtN4 tN4 C WRtN4
tNt Zone C1 tNt Zone C2 tNt Zone C3
63 64 65 66
67 68 69 70 71 72 73 74
CCWWRRtN4 tN4 C WRtN4
tNt Zone C4 tNt Zone C5 tNt Zone C6
75 76
tN4C
Zn Grp C
C2
C3
On/Off
Zone Group
Pump C Delay
Zone Group
Pump C
C4
C5
C6
C5
C6
C1
C1
C3
C2
C4
Limited power available, see wiring brochure
77 78 79 80 81 82 83 84 85 86 87 88
Zone C1 Zone C2 Zone C3 Zone C4 Zone C5 Zone C6
C
Vlv
C
Vlv
C
Vlv
C
Vlv
C
Vlv
C
Vlv
Made in Canada